Hello!
Following are the list of coaching institutes in Lucknow:
1. ALS IAS coaching, Lucknow
2. Plutus academy, Lucknow
3. Race IAS classes, Lucknow
4. Sarthak IAS classes, Lucknow
5. Prepare IAS coaching, Lucknow
6. Prayatna IAS coaching, Lucknow
7. Dhyeya IAS coaching, Lucknow
8. Chayan IAS coaching, Lucknow
9. Rao IAS coaching institute Lucknow
10. Srishti IAS coaching center, Lucknow

Some of the best IAS Coachings in Pune are:

• Vihaan IAS Academy for UPSC Preparation
• Paradigm IAS Academy Private Limited
• Chanakya IAS Academy
• Golden Career Academy Pune
• Kautilya's UPSC Coaching
• ALS IAS Coaching Pune Branch
• HV Desai Institute for UPSC Preparations Pune
• Sankalp Academy

Here is a list of some of the best IAS Coaching Institutes in Delhi:

• Vajiram and Ravi Coaching
• Plutus IAS Academy
• Analog IAS Coaching
• Ramanasri Institute Delhi
• ALS IAS Coaching
• Drishti IAS 
• Khan Study Circle
• Bajirao IAS Institute
• Sriram's IAS Coaching Delhi
• Vision IAS Delhi

Hello aspirant,

There are many IAS coaching centres throughout the country. You will find the best of them in the following cities-

Pune

Delhi

Mumbai

Bengaluru

Bhubaneswar

Ahmedabad

Ranchi

Chennai

Guwahati

These cities have hubs of coaching institutes and have been listed out as per the quality of education available.

dear aspirant,

You can build a base for the subject by going through all the NCERT books from class 6th to class 12 th.

Other books you could refer for optionals:

• Geomorphology by Savindra Singh
• Climatology by D S Lal
• Physical Geography by Savindra Singh covers geomorphology, climatology, biogeography,oceanography and environment geography. ONE book for complete PHYSICAL GEOGRAPHY.A MUST READ.
• Models in Geography by Majid Hussain.
• Geographical Thought by Majid Hussain or R D Dixit
• Human Geography by Majid Hussain
• INDIAN GEOGRAPHY by D R KHULLAR or R C Tiwari. ( both are equally good)

hope it helped.