i want to launch a instance with user data but not able to do

The error message is specific in stating that the t2.micro instance cannot be requested in AZ ap-south-1c. You need to launch the instance in either of ap-south-1a or ap-south-1b or change the instance type to a supported one in ap-south-1c

When launching EC2 instance, if you don't make any changes to Network Settings the default for Subnet is "No preference (Default subnet in any availability zone)". Since AWS is trying to launch one in ap-south-1c, you need to override that auto assignment. You can edit that Subnet preference by editing the Network settings.

--Syd

Your user data looks fine and as per error you dont have t2.micro availability within the ap-south-1c , either you go for other az without specifying the az within configuration or you can also request to have t2.micro instances available in same az from support.

One more option is change t2.micro to other instance type.. You can check the limit section to check what all availability of instances are there within your account.