Create an AMI of the server running in the North Virginia region. Once the AMI is created, The administrator would need the 12 digit account number of the #2 AWS account. This is required for copying the AMI which we have created.
Once the AMI is successfully copied into the Mumbai region, you can launch the instance using copied AMI in the Mumbai region. Once the instance is running and if it's completely operational, the server in the North Virginia region could be terminated. This is the best way to migrate a server to a different account without any hassle.