H1B-visa question

USA H1B Visa
1

Sir ,I have approved H1B Cap 2015 petition till July 2018, Now H1B amend petition also got approved that is also valid till july 2018 and In LCA valid from Mar 2016 to Mar 2019, So Can I stay in US till Mar 2019 or I need to extend after july 2018 to continue stay in US.

Thanks

2

Your stay is governed by 797 and I-94 expiration dates. If they are valid till July 2018, then you can stay only until then. Extensions can be filed 6 months prior to their expiration date.