1. Can i use a 50 amp esc for the a2212 2200 kv motor??

2. Can any one suggest a low weight 3s lipo for 1000kv motor with 30 amp esc. Can i use a 3s 1000 mah lipo?

Yes

@raghul nambi,

Better to have a single thread. I've locked the other one.
Now you have two queries on one thread.

Can I use a 3s 1000mah lipo?
Can I use 50 amp esc?

The answer to both is YES.

But more to it than that.
That 2212 motor draws 10-12amps. (If you're using the right prop, typically between 8x4 and 10x5)
So a 20amp ESC is enough. A 50amp ESC will also work, but will add weight.

C ratings of lipos are often exaggerated. I restrict myself to 10C from lipos rated 20-30C
A 3s 1000 mah lipo of 20-25C rating is fine for your 2212 motor.
Will be around 90-100gms.
If you use a lighter one, it will be of lower capacity, so will give less duration.
Or will die of overload 

Hope this helps
Regards