ANSWER:

Your whole prayer is invalid if you didn’t say the inaugural takbeer! 

You must start the prayer all over again. 

My first rakah is void if i don’t say takbire tahrima i.e. Allahuakbar so my question is in which rakah should i sit in tashhahud if i remember it in my first rakah after reciting the surah fatiyah, as my 1st rakah is void so my 2nd rakah would be the 1st and i should sit in 1st tashahhud in the 3rd rakah which will automatically be my 2nd because my 1st was void and do sajda sahu?

Prayer |