I am about to finish the organic chemistry syllabus for IITJEE. I have been learning from Brilliant tutorials materials. They have mentioned a lot of reactions which are not in the syllabus for IITJEE. I referred some other books for IITJEE as well, and they too have mentioned these reactions which are not in the syllabus. Do I have to study these as well or should I just go as per the syllabus( study only the reactions menitoned in the syllabus)

I also want to know whether Brilliant tutorials postal materials ( 1yr IITJEE) are enough, or should I go for more materials. I am looking at Arihant for problems alone.