EB2, if H1B has been used for 6 years, your H1B can be extended (renewed) for 3 years if you have an approved, pending I-140,
in this situation, can you change employer (H1B transfer), can you still get 3 years H1B one time?
(sure, I know your new employer should apply new PERM and I-140 for you, and you can use old I-140 PD)