I will be residing in Karve Nagar, Pune for next few months. I need a good Internet service. Maximum budget is 1k/month. Not much downloading (around 20-25gb / month if I get good speeds).
How much Speed would you need? Even you can download 25-30Gigs at 256kbps.
^ I would Recommend Reliance Broadband in Pune. I've Heard other broadband providers are not up to mark You could even try BSNL(caution)
Not less than that 
I will call reliance and ask for availability in my area.