MBA @ 5 + years of experience - Crossroads- Prospects / ROI afterwards

Hi, I am having 5 years of total work experience (yet another IT guy! plus an elec engineer from one of top institutes in india) currently in the process of moving back to India as I have accepted offer with an investment bank in their tech divi…

Hi,
I am having 5 years of total work experience (yet another IT guy! plus an elec engineer from one of top institutes in india) currently in the process of moving back to India as I have accepted offer with an investment bank in their tech division....The offer is decent (INR 16lpa plus 2.5l joining bonus). I am keen to get out of IT industry and move to non profit consulting but I feel bit trapped out here 😃 Well i was a hard core techie...
I do not want to do my MBA abroad as it would lock me down abroad for years as I would tryto pay back the mba cost and it is prohibitive if I do not take up I-Banking line etc ...
What options do I have in addition to ISB... ? How do I calculate ROI for ISB/IIM-PGPX etc.
How realistic is to expect a career change after 1 year of MBA (my interest is to work in consulting in social sector for international organizations) and what are prospects @ ISB / IIM-PGPx
Right now the 'cost'(or a investment) of doing an MBA is a year of my salary and fees ... that will work out to around 36-40 L atleast..
I am having pretty good extra curriculars with variety of non profits on various activitiesfrom fund raising, marketing, creative campaigning etc.
( hmm poor acads in college though! 😉 6.8 GPA with 'extreme' grades in both ends of grading depending on my interest / lack of it in the subjects. good acads in 10th and 12th)

Any suggestions / pointers and discussions would be greatly appreciated.
regards

(Apologies I first posted this question in the incorrect forum in Career Discussions and not able to delete it. Request the moderator to close it there please)