Budget brands for gears in India A total newbie here. I'm planning to upgrade a single speed to geared one road/tour bike. I haven't decided the gear system though. I guess I'll decide that upon availability of the parts. 

Well, I am looking for a budget but reliable alternative to Shimano brand gears. 

I live in India. Can anyone suggest some other brands? Also are there any local companies?
Changing major features of a bike (e.g., drop/flat handlebars, gears/no gears) is rarely an economical option. There are all kinds of compatibility issues (e.g., different drop-out width, nowhere to mount a derailleur, etc.) and overcoming these takes time and money and tends to leave you with a worse bike.

Usually, the most economical and most effective way of making this kind of major change is to sell the bike you don't want and buy the bike you do want, possibly second-hand.