Goa in March
 

Sorry Mark forgot to add this...
Also I have a couple of mates coming out a few days after me and looking to buy a Enfield also, is there anywhere they could go to pick up one, or a used bike web site for buying one?

If he is an Indian citizen or resident no problem, my bike is registered to a friend in Mumbai. I found my bike here which is very much like Gumtree.

Used Bikes & Scooters for Sale in India | Buy Second Hand Bikes Online - Quikr

Hi mate, you also need a Polution Under Control Certificate (PUC) hopefully you're mate can sort that out when he picks up the bike for you. If he doesn't, You can get one get one from a petrol service station or a mechanic, you may have to pay for a service first but at 2000 INR it's pretty cheap
If you don't get one, the fine is 1000INR first time then 2000 INR for the second, I'm not sure but it may just keep going up after that, (so I was told, from a pretty unreliable source)!
My tip, the Enfield is a fantastic bike, just keep servicing the bike every 1000 - 1500 kilometres and she'll keep on going and going, oh and check the nuts every now and again, I'm envious, I had a great trip there last year looking forward to getting back there in a couple of years,

If a bike is bought in india is it possible to take it to nepal or do i need a carnet?

Yes it is possible to take it to Nepal, you just pay at the border, it is not possible to get a carnet in India.