1. Invite your parents under your H1B, you still have 5 months available, should be OK for they are supposed to stay for 3 months. Timing is OK.
2. Change your H1B to H4 under your wife's H1B. Then your parents could also be invited to America.
2. Change your H1B to H4 under your wife's H1B. Then your parents could also be invited to America.