H4 to H1 conversion complication

My spouse got his L1 to H1 COS approved last year in Oct 2012 and my L2 to H4 was applied. We did not get any approval until March 2013. X company applied H1 for me and it was approved in the end of april 2013. Me and my spouse left to India for stamping his H1 and my H4. Stamping was done and we came back in May 2013. Now, as my I-94 changed, is my H1 valid from 1st October 2013? Due to some personal reasons, I am not working for X company. Y company has come forward in employing me. Am I on H1 or H4? How can I join Y company, is it through H1b transfer or H4-H1 COS?

Was your H-1 approved w/ COS in April 2013? If yes, then you are on H-1 from Oct 1. This is b/c your most recent I-94 will be the one approved in April 2013. It has a start date of Oct 2013, which trumps the start date mentioned in the I-94 received when you entered US on H-4.