I am currently on H4 visa & my H1B application got picked up in lottery 2017 but my I94 expires in Sept 2016 & h4 visa is valid till Sept 2017. Do I need to extend my I94??
Also, if I apply for an extention of I94, will it overrite my H1B visa??
You will have 2 pending applications in this case - H-4 extension and H-1 COS. The one that is approved later will determine your eventual status. Search for Last Action Rule.
I got my problem solved i.e I got my i94 with new dates as per the latest h1b petition of my husband by sending an email and the required documents to the CBP(suitable for me). They issued me an entirely new i94 within a day.