Read this CAR to get an idea what you need to do to make the rating current again
http://www.dgca.nic.in/cars/D8F-F1.pdf
You can approach CAE Bangalore or FSTC Gurgaon to get it renewed
P.S : If you have 3000 hours on 737 NG how come you havent flown somewhere for so long ? If you were medically unfit shouldnt your company be renewing it for you ?