Hi Karthik,
That's a wide open question! Which parts of Compliance and Customs Management are you using?
I your new country already localised for GTS? That's to say, do the relevant Legal Regulations already exist in the system? If so, most of the work should already be done.
You will need to map the Company Code and Plant(s) to new Foreign Trade Organisation and Legal Unit(s), and extend the Control Settings for Document Types to the additional Legal Regulation. You should also check the assignment of Numbering Schemes to that Legal Regulation.
With more detailed information about your requirements, there may be more to add.
Regards,
Dave