My boyfriend is on probation he violated last year and served his time.He got out of prison and did 3 months of house arrest.Now he is still on probation for 10 more months.I need to know now that he violated again and he only has 10 months left will he only do the 10 months or will he serve more time?

He wouldn't serve more time unless the violation involved another crime. Like if he did something simple like miss a court date then he probably wouldn't get more time.
If his violation was a DUI and/or driving with a suspended license then yes he could be looking at more than the 10 months
At least that is the way it works in my neighborhood.