Can a veteran (not on active duty) that receives tuition assistance from a reserve unit be paid tuition assistance and (Chapter 30) benefits for the same course?

​Yes. However, due to the limited amount of money the military has for tuition assistance (TA) benefits, the military may choose not to provide TA to individuals who are in receipt of chapter 30 benefits.

https://www.tsc.fl.edu/student-life/veterans-affairs/guidance-for-choosing-gi-bill-programs/