Roshni Ma'am's one shot videos will give great conceptual clarity. But one shots are mainly for NCERT. 

For JEE level, you will have to dig a little deeper to develop different approach to solve JEE questions quickly.

So, I would recommend you to watch one shot videos first to clear all your basic concepts first so that when you study that chapter for JEE level you can understand higher level concepts easily.

For JEE preparation, please follow JEE pe JEET series regularly along with one shot videos of Roshni Ma'am.