Honestly speaking, it sometimes depends on the Teachers. Not all FIITJEE Branches have good Teachers. If youre from the Delhi NCR/Northern Part of India, or Hyderabad/Chennai or Eastern Part, still Fiitjee is a good option. From My Experience, Study Material as well as Test Series of Allen/Resonance are more effective than Fiitjee, considering youre an Good Student aspiring a seat in IIT or NIT. Hence, when you choose the coachinh center consult, your immediate seniors regarding the Faculty first as well as Timings, Batches, Etc. Many times Local Coaching Institutions are much better than Branded ones, where you have a better Teacher Student Ratio and Good Faculty. You may parallely take Material from Allen/Resonance as well as Many Good Online Platforms for Preparation.