Thank you for your question. 

JEE is a tough exam to compete.

To crack it , you must practise numericals as much as you can as physics chemistry and maths are majorly calculative.

Online programme of mostly every institute is available and most are same  

The thing which can change is how much you practice mcq.

PHYSICS: CENGAGE Series / BANSAL CLASSES

CHEMISTRY : RESONANCE / VIBRANT ACADEMY

MATHS: CENGAGE Series / ALLEN / VIBRANT

These quick test series for last minute preparation is recommended. 

AITS by FIIT JEE > Bansal Test Series for Advance . Resonance Test Series .Vibrant Test Series .Allen Test Series

Good luck