Welcome to e health forum.
Guidelines with regarding to HIV screening and testing are not different in any part of the world. Everywhere the same universal policies and testing is conducted.
Yes, in very low risk cases of exposure, a negative result with a 12 week Antibody test for HIV can be considered as conclusive. But each case is different and need for additional testing should be determined by consulting with a HIV counselor or your doctor.
If your doctor feels that you are at a higher risk, then he may advice additional testing at a later date.
Yes, 4th generation HIV tests are available all over India, in most accredited private laboratories like Religare, Private hospitals and Government and National Aids Control Organisation run clinics.
I hope this helps.