Almost all parts of India is having high humid climate. Mumbai, Chennai, Kolkata and seashore area are having almost more than 70% humid climate in most of the time. In Humid climate, Air Cooler is not effective at all, All brands Air Cooler will not be able to cool the room. It will simply give air just like fan, so instead investing your money in Air Cooler, Cheap fan will work similar to Air cooler works.
Rajasthan is more dry state, Air cooler effectively cools the room in Rajasthan. In Other parts of India March, April, and May are relatively less humid, so Air Coolers able to cool the room in these months slightly. In monsoon season, there is no use of Air Cooler. In Humid Climate only Air Conditioner can cool the room air.
There are Few brand which makes good Air Cooler, Following are the brands
1. Symphony Air Cooler
3. Bajaj Air Cooler
The price range is from Rs 5000 to Rs 10000. Some local electrical shop also makes cheap Air Cooler in India, But that are not safe. So always buy branded Air Cooler.
Air Cooler makes room more humid, which is not comfortable and it leads to lots of other problem. If possible buy Air Conditioner instead of Air Cooler.