can anyone recommend me something like that, for example faking transcript, then pushed into leader role because of the excellent (fake) ability? I want to see protagonist in tight situation because of his/her lie, and had to fake it until he/she can make it. As long as it is not yaoi/yuri (or any romance honestly, but it is alright if it contains some) I'm alright with it.
To Be a Power in the Shadows kinda fits. He tries to play the part of a NPC but is pushed into responsibilities
He has the ability though, he plays the part he doesn't have the ability on his secret identity, but he does have the ability to do whatever.
The closest tag you should searched is 'Misunderstanding'. From there, the closest that I've read is Battlefield: Masurawo. I could be wrong though.
The Deer and the Cauldron The protagonist manages to become one of the emperor's most trusted agents while simultaneously being one of the leaders of a rebel group looking to overthrow said emperor. All of this while he's illiterate, knows barely any martial arts, and barely has any clue what he's doing half the time. The protagonist has to rely on his wits and his quick tongue to get out of trouble all the time (and sometimes into trouble!) It's great fun.
Please make your reading list public. The Amber Sword might fit your bill, the MC isn't exactly faking competence as much as making people assume his identity to be much higher than it actually is. So he is able to lead people and influence people because of their assumptions about him. Aka, he fakes it until he makes it. So by the time they figure out he wasn't actually what they thought, he is high enough position at that point for them to accept it.
Hmm... my account for reading is different than this. How do I link one? @Miku is mine. Edit: try this? https://www.novelupdates.com/readlist/?uid=156112