Earlier the papers were valid for two years. I don't know what is the present status. You will have to refer to DGCA CAR on their website. I really suggest you do some reading in the CAR Flight crew licensing section. I think you should call some Indian flying clubs (I'm not sure which ones are good) and speak to a couple of CFI's or pay them a visit. They would be much better informed to help you. Also I must add that I had a doubt once and I called the DGCA office. I was left completely shocked as the guy at the other end went out of the way to help me. So don't be shy to call them. For R/T renewal see WPC website too. Wireless planning and co-ordination. Guys here were not helpful to me. But maybe you will get lucky. Try giving them a call too.
You have a long road ahead. And the person who will help you the most will most likely be yourself.
Beware of cheats. There are too many around. So cross check with more than a few people before reaching for your wallet.