hi renukabhusari,
Please let us know in which state are you coming because many things depends on that,now for the common requirment of documnents you will be having all the copies of your marksheets(attested from US)
but first you know which Credentialising agency is required by your state than go to their website and follow the instructions.
In Later stages you will be needing many documents which should be posted to CE agency dirctly by your college itself.
The Federation of State Boards of Physical Therapy is a common website,must be knowing...go through it !

Best Wishes
Pallavi