回复：请问大家 TN 签证可否直接办绿卡。

办绿卡 has nothing to do with your current non-immigrant status. It depends on your (or your sponsor's) eligiblity for GC categories.
You can do it in TN, F1, B2,...or out-of-USA, the trick is, you won't be able to renew or extend these status (not allowing immigrant intent) or get visa stamp in those classifications after you file I-140/485