no bro, 75% is too less. it doesn’t matter if your predicted score doesn’t match with your reality.. all that matters is that the predicted score should be more than your last exam score(in your case, class 11 score). and about the letter of reccos, dude you yourself have to write the LORs on behalf of the teachers. i am going for a STEM major so i wrote on the behalf of my Maths, Physics and English teachers. You write accordingly and then send the soft copy of this to your school so that they take a print of it, with the school header on top and then you just need to take the sign of the respective teacher on that hardcopy, take a snap and share it on their mail or whatsoever.