Hi Anil,
Being in London and the cost of living is very expensive.
But here are some details:
If you are staying in a flat on sharing basis rent will be apprx. be 300-500 pounds per month but if need a flat to stay alone or with your family then it will cost 500-700 pounds per month as my friend is staying in London and working there from last 5 years.
I have attached a word doc. which will give you more information.
Have a look and let me know if this helps you.
Me too applied for UK Visa, lets see when i will get the Visa.
Take care
Arati
(astarkaps1@gmail.com)