I have H1 b visa valid till 31 July 2019 and prepared document for extension send to my employer but
I travelled to India on 5 April 2019 because of demise of my father and stayed there till 10 may 2019 . Even I informed the same to my employer about my travel but they missed to inform the same to vendor for holding my extension until return. So vendor applied the extension on 30 April 2019 and I was not aware about. I came back to US again on 10 May 2019 and my i94 valid till 10 Aug 2019 . So please suggest what are the implication for the same that extension applied on my last i94 and at the time of submit I was in India.
There will be no implications, all goes well.
Usually, your I-94 is closed, when you exit the country, so your I-94 would not have been valid, if they verify it. It is better you discuss with your attorney, who filed H1B and send them the latest I-94 after your travel. CheckHow to print I-94 Online. Your attorney can send the latest I-94 to USCIS as additional information, so that the application is complete.
I re-read the question after @Kumar 's above reply.
There is something good and something bad in the situation.
Good: I-94 is to prove that the candidate has maintained legal status while in USA. With that respect, the petition-attached I-94 is valid to show that the candidate has maintained valid status(never illegal) in US.
Bad: Since the petition was an extension of current status(H1) which you dont have it when its filed (since you are out side of US), the petition in totality is INVALID.
What to do: Your employer must file a new extension petition using your latest I-94.