How much should a tenant pay as a security deposit?

Usually the tenant has no choice in the matter but to pay as deposit what the home owner demands. The standards vary from city to city.

In Bangalore, for example, the typical security deposit is usually 10 times the monthly rental. In Mumbai, this is usually 4-5 times the monthly rental. 

There is legislation in the making, the so called model tenancy law, that might cap such security deposits to 2-3 times the monthly rental.

However the suggestion would be to talk to the home owner and see if the security deposit can be more reasonable rather than a large number.