Please find out the name of the other college.
MIT is in Cambridge, virtually in Boston. Additional advice will depend on the location of the second school, but...
Providence is 52 miles from Boston; Manchester is 50 miles.
You could conceivably get from Providence to Boston by train, train and subway, or bus - all time-consuming and not necessarily efficient.
You could take a taxi, car service or possibly shuttle from PVD or MHT to Boston - potentially expensive.
You could rent a car at either airport. Driving in Boston is difficult and parking is VERY expensive. Also, there could possibly be a surcharge for taking the rental car out of the state in which you rent it.
ATA does code-shares with Southwest - if you're coming from Austin or Houston, this could be a viable option which would have you fly in and out of Logan (less than two miles from Boston) at Southwest-like fares IF you book through Southwest. Sample: Houston-Hobby to Boston 1/11 - 1/15, $123 each way plus tax.
While Southwest may have the cheapest flights from your home airport to New England, you have to add in all the additional costs to see if you'd really be saving money by not flying into Logan on SOME airline.
Of course, if the other school turns out to be, I dunno, New Hampshire College, then flying in and out of Manchester would make some amount of sense.