Hello,

Both the channels are fantastic to prepare for your JEE mains as well as advanced. You have to choose it according to your needs and necessities as to whose content you are able to understand it in a better way. Everyone has a different set of opinions and understanding capacities, so you have to choose it accordingly.  But I'll suggest you should go for Mohit Tyagi Sir's YouTube channel as the content provided there is unmatched and he is one of the best online teachers for the preparation of IIT JEE. You can completely rely on his channel to take proper guidance and to do your hardwork in the right direction. And also if you want to study for advanced then Mohit Tyagi sir is the best but alakh sir is also good if if you are focusing only on your mains.

But at last you have to choose for yourself by following some video's of both the channels and to get an idea of how they teach and whose style of teaching suits you more and you are able to understand more.

Thank you!