H1 and H4 order of approval when in India and how to enter

[kiran_dj]

I am in india and we have applied both H1 and H4 visa .

Senario 1 - H1B is approved first and H4 visa after that, and I am still in India.

Senario 2 - H4 is approved and then H1 B after that, and I am still in India

- Can I enter US on H4 and then use COS to convert to H1B will it be valid in both senario. Need help.

Senario 3- Can I travel to US on approved H4 when my H1B approval is pending and then do COS?