Which insurance scheme is best?

There are two types of insurance- Life and non life. I hope, you are talking of life insurance.

The purpose of life insurance is to provide maximum security to dependant in the event of unfortuate event of life insured. A low premium and high risk cover policy should be selected. There are policies that will pay nothing if the insured lives for a certain period and will pay to dependent only (not the insured) if the insured dies before the stipulated date. I favoor such policies. These are also called term policies.

I think kotak life insurance is good which is old mutual life insurance provide 5 lacs if death occurred and other 10 return if withdraw in between.

There is no such policy as best as this field has too many players including the private ones which are packaging their products claiming to be the best.It's better to make a comparative study and then take an informed decision.