The languages with full departments, and the ability to go to higher levels are the Romance languages (French, Spanish, Italian), and German, Chinese, Japanese, Arabic and Hebrew.
You can see the department pages to look at specific classes offered.
Department of Romance Languages - Tufts University or
Department of German, Russian & Asian Languages and Literature - Tufts University .
Generally Hindi is not offered, a group of students petitioned to have it offered but were turned down 2 semesters in a row, so we kind of gave up on it. It has been offered in the past as an Experimental College class, but not for a while.