Thanks everyone for helping me out and finding the best broadband as per my budget and needs.
Now I think I have a stable Internet and with better service than MTNL for sure. But I still need answers to a lot of questions. The questions pertain to Pacenet or login based browsing ISP in general. So discussing these questions here would not serve justice to this thread. It would be offtopic. So I have created a separate thread for the same. I would request you to participate here:
*www.thinkdigit.com/forum/broadband...peeding-up-peer-peer-sharing.html#post2056707
As far as answer to this thread goes, I have reached to the following conclusion.
For someone looking at reasonably high speed Internet under 1000 in Delhi, then there are not much choices.
MTNL: A 1 Mbps connection from MTNL will cost you above Rs 1200. So it might not be in budget for some. And if you can ignore their customer service and stable albeit long down-times when its not stable connection, then you can go with MTNL.
Airtel is very expensive. But with best customer service. They would come at your doorsteps within hours of registering your complaint. But they charge a premium for this service. You can't get a 1 Mbps connection under 1k for them.
Reliance has awesome plans and I was about to take their broadband but their cons overshoot their pros. Disconnecting a connection from Reliance can be a PITA, and which I think will be my requirement in near future. Once I am settled I can move to Reliance later on.
Spectranet has good plans. But due to them giving fibre optic lines, their service is (very) limited. You may ask whether they provide the service to your area, albeit with less hope. But if you do manage to get a connection, it would be one helluva ride of Bandwidth you will receive! That too under 1k.
Pacenet is a good ISP. Works on Login based session. Which means you have to login before accessing Internet. (Refer thread linked above.) And they have a good True unlimited plan of 1 Mbps under 1k.
Hathway: I only heard about them today after I took a connection from Pacenet. Also work on Login based session. But their plans seems lucrative. You can also give them a call and ask if "Ultra 1 Mbps" plan has FUP. If its true Unlimited, then at Rs 2100 for 3 months is more than worth it!
Hope this helps someone looking for answer to the "Best Broadband in Delhi for Under Rs 1k" question.