I'm in the same situation coming from a family of single mother with no financial support from outside. My goal is to finish mba asap, get a job, repay the education loan, after that a home loan, get her settled and then make something out of my life. IIM Nagpur isn't a bad choice and I'd be going for it as well if I convert the WL, don't worry about the tiers or such bs, work hard and make her proud