ANSWER:

You must not recite it when the Imam is reciting.
You can recite immediately after the imam is done or you can even skip it as imam’s recitation suffices for the followers in loud rakahs. 

When to read sura fatiha in solah 1. same time every sentence with imam or 2 should recite the sentence just after imam finish a sentence or 3 after imam completes the surah?

Prayer |