Firstly, the baggage allowance will be whatever Kingfisher gives you because they are the first carrier and others have to honour it.

Secondly, when checking in at BOM, make sure your baggage tags and receipts are marked all the way to GVA. The lugguge should go all the way to GVA without you having to pick it up anywhere. Bonus is that Kingfisher and KLM are in the same terminal (LHR T4) and handled by the same agents (Cobalt previously known as KLM Ground Services)

Thirdly, when checking in with KLM at LHR, give them the baggage receipts numbers to verify that their system has the same numbers. Any discrepency will mean that your baggage will not be loaded onto the KLM aircraft at LHR due to strict security rules in place.

If everything goes swimmingly and as you say, everything is on one ticket, you will not have to worry about anything.