I was asking because my brother visited US on visitor visa last year. When he was here, I applied for his GC, and he went back to Nepal. He still has 4 years left on his visitor Visa but his GC application is still pending.

Since he still has legal visa, but I am not sure if he can use that visa since now he's on the process for GC which I heard takes 10 years. Is he able to use his visa to visit?