My favorite is the Black Diamond meeting that meets in Waltham which was actually last night so have to wait a while for that one.  

In addition, Black Diamond (url in my signature) is having a meeting on 1/27 on "Packaging your Commercial deal for the best rates, terms and sources of funds". 

The ones that I know about are the RI Real Estate Investors Group and Black Diamond Real Estate Investors. 

Though fortuitously probably the best meeting is the closest to you, the Black Diamond meeting in Waltham (2nd one in Worcester).  

Going to little farther I would highly recommend checking out the Black Diamond meeting in Waltham (2nd location in Worcester).  

I regularly hear from people asking me if I am expanding Black Diamond into Western MA.You probably already know about CTREIA. 

You should reach out to @Ann Bellamy with Black Diamond and @Justin Silverio for free networking resources. 

If you are willing to go a little further there is the Boston AREIA in Medford and, IMO the best local event, the Black Diamond meeting in Waltham.

The best bet right now would be the Black Diamond meeting in Worcester.  

There are a few meetings on the North Shore, @Justin Silverio hosts a quarterly meetup in Reading, the Boston Area REIA in Medford gets a lot of NH people and the Black Diamond meeting in Waltham is IMO the best local event right now and well worth the ride.