Try meeting few stock brokers and collect lots of information. Tabulate it and you will know exactly what u r looking for.
One basic information should be "floor" or "stop loss". Simply put how much money u r prepared to lose out of ur capital. Tell this in very clear cut terms to ur Portfolio Manager.
Another is how much fees u should pay and should there be any share in profits.
These two are most important to reach a decision.
A minor point to discuss is what sectors u wish to be in. Particularly if you are religious minded. Many investors do not wish to be in tobacco or alcohol companies or some such taboo companies. If u have such reservations, tell this to the Portfolio Manager.
If u mean "lots of profits" by "reliable" - sorry but nobody can predict about markets properly and 100% sure shot ways. One can not time the markets always and every time. Please remember this when ever u discuss with ur Portfolio Manager.
Few top class brokers do include Kotak. But then almost all brokerage houses are equal in almost all parameters.
Wish u all the money in ur portfolio soon.