Use DescribeOrderableDBInstanceOptions with an AWS SDK or CLI

    /// <summary>
    /// Get a list of orderable DB instance options for a specific
    /// engine and engine version.
    /// </summary>
    /// <param name="engine">Name of the engine.</param>
    /// <param name="engineVersion">Version of the engine.</param>
    /// <returns>List of OrderableDBInstanceOptions.</returns>
    public async Task<List<OrderableDBInstanceOption>> DescribeOrderableDBInstanceOptions(string engine, string engineVersion)
    {
        // Use a paginator to get a list of DB instance options.
        var results = new List<OrderableDBInstanceOption>();
        var paginateInstanceOptions = _amazonRDS.Paginators.DescribeOrderableDBInstanceOptions(
            new DescribeOrderableDBInstanceOptionsRequest()
            {
                Engine = engine,
                EngineVersion = engineVersion,
            });
        // Get the entire list using the paginator.
        await foreach (var instanceOptions in paginateInstanceOptions.OrderableDBInstanceOptions)
        {
            results.Add(instanceOptions);
        }
        return results;
    }

        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::RDS::RDSClient client(clientConfig);


//! Routine which gets available 'micro' DB instance classes, displays the list
//! to the user, and returns the user selection.
/*!
 \sa chooseMicroDBInstanceClass()
 \param engineName: The DB engine name.
 \param engineVersion: The DB engine version.
 \param dbInstanceClass: String for DB instance class chosen by the user.
 \param client: 'RDSClient' instance.
 \return bool: Successful completion.
 */
bool AwsDoc::RDS::chooseMicroDBInstanceClass(const Aws::String &engine,
                                             const Aws::String &engineVersion,
                                             Aws::String &dbInstanceClass,
                                             const Aws::RDS::RDSClient &client) {
    std::vector<Aws::String> instanceClasses;
    Aws::String marker;
    do {
        Aws::RDS::Model::DescribeOrderableDBInstanceOptionsRequest request;
        request.SetEngine(engine);
        request.SetEngineVersion(engineVersion);
        if (!marker.empty()) {
            request.SetMarker(marker);
        }

        Aws::RDS::Model::DescribeOrderableDBInstanceOptionsOutcome outcome =
                client.DescribeOrderableDBInstanceOptions(request);

        if (outcome.IsSuccess()) {
            const Aws::Vector<Aws::RDS::Model::OrderableDBInstanceOption> &options =
                    outcome.GetResult().GetOrderableDBInstanceOptions();
            for (const Aws::RDS::Model::OrderableDBInstanceOption &option: options) {
                const Aws::String &instanceClass = option.GetDBInstanceClass();
                if (instanceClass.find("micro") != std::string::npos) {
                    if (std::find(instanceClasses.begin(), instanceClasses.end(),
                                  instanceClass) ==
                        instanceClasses.end()) {
                        instanceClasses.push_back(instanceClass);
                    }
                }
            }
            marker = outcome.GetResult().GetMarker();
        }
        else {
            std::cerr << "Error with RDS::DescribeOrderableDBInstanceOptions. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            return false;
        }
    } while (!marker.empty());

    std::cout << "The available micro DB instance classes for your database engine are:"
              << std::endl;
    for (int i = 0; i < instanceClasses.size(); ++i) {
        std::cout << "   " << i + 1 << ": " << instanceClasses[i] << std::endl;
    }

    int choice = askQuestionForIntRange(
            "Which micro DB instance class do you want to use? ",
            1, static_cast<int>(instanceClasses.size()));
    dbInstanceClass = instanceClasses[choice - 1];
    return true;
}

To describe orderable DB instance options

The following describe-orderable-db-instance-options example retrieves details about the orderable options for a DB instances running the MySQL DB engine.

aws rds describe-orderable-db-instance-options \
    --engine mysql

Output:

{
    "OrderableDBInstanceOptions": [
        {
            "MinStorageSize": 5,
            "ReadReplicaCapable": true,
            "MaxStorageSize": 6144,
            "AvailabilityZones": [
                {
                    "Name": "us-east-1a"
                },
                {
                    "Name": "us-east-1b"
                },
                {
                    "Name": "us-east-1c"
                },
                {
                    "Name": "us-east-1d"
                }
            ],
            "SupportsIops": false,
            "AvailableProcessorFeatures": [],
            "MultiAZCapable": true,
            "DBInstanceClass": "db.m1.large",
            "Vpc": true,
            "StorageType": "gp2",
            "LicenseModel": "general-public-license",
            "EngineVersion": "5.5.46",
            "SupportsStorageEncryption": false,
            "SupportsEnhancedMonitoring": true,
            "Engine": "mysql",
            "SupportsIAMDatabaseAuthentication": false,
            "SupportsPerformanceInsights": false
        }
    ]
    ...some output truncated...
}

import (
	"context"
	"errors"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/rds"
	"github.com/aws/aws-sdk-go-v2/service/rds/types"
)

type DbInstances struct {
	RdsClient *rds.Client
}



// GetOrderableInstances uses a paginator to get DB instance options that can be used to create DB instances that are
// compatible with a set of specifications.
func (instances *DbInstances) GetOrderableInstances(ctx context.Context, engine string, engineVersion string) (
	[]types.OrderableDBInstanceOption, error) {

	var output *rds.DescribeOrderableDBInstanceOptionsOutput
	var instanceOptions []types.OrderableDBInstanceOption
	var err error
	orderablePaginator := rds.NewDescribeOrderableDBInstanceOptionsPaginator(instances.RdsClient,
		&rds.DescribeOrderableDBInstanceOptionsInput{
			Engine:        aws.String(engine),
			EngineVersion: aws.String(engineVersion),
		})
	for orderablePaginator.HasMorePages() {
		output, err = orderablePaginator.NextPage(ctx)
		if err != nil {
			log.Printf("Couldn't get orderable DB instance options: %v\n", err)
			break
		} else {
			instanceOptions = append(instanceOptions, output.OrderableDBInstanceOptions...)
		}
	}
	return instanceOptions, err
}

class InstanceWrapper:
    """Encapsulates Amazon RDS DB instance actions."""

    def __init__(self, rds_client):
        """
        :param rds_client: A Boto3 Amazon RDS client.
        """
        self.rds_client = rds_client

    @classmethod
    def from_client(cls):
        """
        Instantiates this class from a Boto3 client.
        """
        rds_client = boto3.client("rds")
        return cls(rds_client)


    def get_orderable_instances(self, db_engine, db_engine_version):
        """
        Gets DB instance options that can be used to create DB instances that are
        compatible with a set of specifications.

        :param db_engine: The database engine that must be supported by the DB instance.
        :param db_engine_version: The engine version that must be supported by the DB instance.
        :return: The list of DB instance options that can be used to create a compatible DB instance.
        """
        try:
            inst_opts = []
            paginator = self.rds_client.get_paginator(
                "describe_orderable_db_instance_options"
            )
            for page in paginator.paginate(
                Engine=db_engine, EngineVersion=db_engine_version
            ):
                inst_opts += page["OrderableDBInstanceOptions"]
        except ClientError as err:
            logger.error(
                "Couldn't get orderable DB instances. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return inst_opts