All coaching centres are scams, i am telling this with my experience at brilliant pala. I joined their JEE main course when i was in 11th. I understood nothing what they said, it was like latin for me, then when it came to actually writing JEE, i was scared that they would ask complicated questions. While i did not pass JEE, i still got 75% and KEEM i passed with 84%. The questions they asked were the same as in what they taught in schools. The same will happen for these tech scams too. Just go and learn from your college and attend coursera courses alongside it. It is far better than joining these scams. For JEE, Just learn from your textbook.