Dear Angsuman,
Depending on where the flux of activity is higher you can choose to have 30 seats each at four places using the ASP model.
You can have your servers located in US or for that matter in Delhi,India.
You can have IPLC extended to all the locations you want to have your agents/CSRs in India.
This way you will save on cost as well as Bandwidth.
This is a proven solution, working in Bhuvneshwar,Jallandhar,Chandigarh and Ludhiana.
Warm Regards
Deepak