Have you tried googling for the motor? A 5V DC motor in the RPM range you require (I think most run at about the same speed.) are very common. You shouldn't have any trouble finding it.
I think a 5v DC motor with around 1000 rpm should satisfy your requirements.. Measure the current rpm with an rpm counter.
RPM pick-up device is already done by Kadett200is! Check out the adjacent thread.
Most of us are not in your country so if we specify a motor then you won't be able to buy it. You should ask for a motor made in India on an Indian website.
Look at robot sites for motors. You'll probably need one with a gearbox to get a low RPM like 600 or so. This site has some motors, but they don't meet your exact requirements: **broken link removed**
Most of us are not in your country so if we specify a motor then you won't be able to buy it. You should ask for a motor made in India on an Indian website.