I am new to Chennai and how to sort out mosquito menace here! I called somecompanies andwhat you guys think about Phifer? Is it a good decision to go with Phifer mosquito nets ? Please let me know!

Yes, Phifer mosquitos nets are good ones. Mosquitos are real thing there, try to spray or use coil in the evening. And Keep your doors and windows close around evening when sun is setting because that's the time when mosquitos comes inside home when its lights are on. Then later when its night you can open it. Hope it helps.

You are on an international site, mainly reaching the EU and NA. We don't use nets but in SA the zika virus is a downside of visiting, especially for pregnant women. In Ontario Canada where I live, mosquitoes have not been a problem this year. We use sprays. Sorry for not being able to help with the net issue but imagine any net to keep out bugs in your climate would be good.

We bought a mosquito fog machine and a mosquito magnet. Does wonders to keep down the mosquito population in the summer, and we get many.

The fog machine we bough cost around $100CDN. Once you fog you need to stay away from the area for at least 30 minutes because you are spraying harmful chemicals. I much prefer the mosquito magnet which attracts the mosquitos and then kills them without compromising the use of your yard.

A net is a great idea, but I would also look into other options as well, like the fog and the magnet.

The OP is in south India, don't think so they have fog machine and mosquitos magnets available there. What is main there in Chennai is natural home remedies like 'Dhoop' smoke (not sure what they call it in English) which is not bad for health too, it is one of the liquid extracts from the bark of some kind of tree, which they dry it out and it becomes stiffens and they crush it and sprinkle it on the burning coal, so that aroma of it spreads out and repel the mosquitos and it does repel it, its an ancient traditional practice . And some mosquitos repellent Coils that you don't want to spend breathing on too much, and some sprays.
Using net as a protection from mosquito is also a Common practice over there especially at home. I think that would be good choice if for you.