Engineering

Yes, one year is sufficient for IIT preparation.

In my opinion resonance is best for IIT preparation for freshers as well as repeaters. Best of luck.

First of all, thank you for asking question as this is one of the most common doubt of students . Let me clear your doubt
Your rank should be less than 60k and this rank varies from category as you already know. Not only your rank but your percentage also needs to be good for getting CS in GL Bajaj . If due to any reason you don't get good rank in UPSEE exam then you can also take admission directly in GL Bajaj, but for CS your percentage should be more than 80%.

You can follow
Engineering mathematics by N. P. Bali and A. J. George
Engineering physics by S Hand publication. Engineering chemistry by S. Hand publication
Communication skills by S. Hand publication.

The school studies are important as that are the basics of the course but you can't crack JEE Advanced with its help. You should prepare for IIT to crack that.

For JEE Mains preparation, I suggest you Resonance.

Resonance is best for IIT preparation.

Go for NIT because they provide more facility in term of campus placements and other activities.

You can prepare for various government jobs like for junior engineer, GATE preparation and civil services. Join any coaching class and prepare. You can also go for M.Tech to do higher studies.

You can consider following colleges:
College of Engineering Pune
Lovely Professional University
Hindustan Institute of Engineering Technology Chennai, Vellore Institute of Technology
P. S. G. College of Technology Coimbatore
Madras Institute of Technology Chennai, SCMS School of Engineering and Technology Cochin
Veermata Jijabai Technological Institute Mumbai
Anna UniversityCollege of Engineering Pune, Jadavpur University.