If i was in college for 5months with 6 1/2 units, is that considered full time?

[Hal_Al]

Probably not. Your school determines what constitutes full time.  There is no IRS number of units.

That said, the  standard most used, by schools, is 12 hours/units. 

[Opus 17]

If a normal load is 16 units, your school probably doesn't count you as "full time" unless you are taking at least 12 or 13.  But you have to ask your school if you don't know.