Hi Bidyut Kundu!

The best resource that you can get for preparation of Jee mains is if you are from CBSE then, NCERT textbooks are the best resources to crack Jee mains. And if you want to refer different books for each subject then I can prefer you to check:

Concepts of physics vol1 and vol2 - HC Verma

A text book of physical chemistry - Dr. R K Gupta

A textbook of organic chemistry - O P Tandon

A Textbook of Inorganic Chemistry - O P Tandon

Objective mathematics vol1 and vol2 - R D Sharma

For online courses you can refer to:

Ask IITians

Akash i-tutor

Plancess

And coming to the centers in West Benga. Jee Mains center is available all over India and if you specifically want to know the centers in West Bengal then:

Kalyani

Kharagpur

Kolkata

Siliguri

Resonance is a good institute for IIT JEE MAINS & ADVANCE Preparations. Many All India Rankers had joined Resonance to score high in various Engineering Entrances such as BITSAT, AIEEE etc. You can see their past results in their website and moreover, the teachers are also very experienced and cooperative.

Yes there are centres of resonance in Kolkata, Berhampore, Durgapur.

Good Luck

Hello Bidyut kundu 

Yes the Resonance is one of the top coaching center if your comfortable with this better my suggestion for you to join in that but the thing is before going to coaching center please learn all concepts of ncert books and later on some of the reference books and take so many mock tests 

Good luck