Do PYQs from last 5 years. It covers about 70%. If u do 10 years, I think about 90% is done.
Rest make one page notes on topics and read NCERT.
Many coaching are there, though none might be as good in quality as seen for other subjects.
1. FraternityIAS (check youtube for this channel useful strategy to tackle each subject)
2. Lokesh Yadav (saw a few demo lectures on a telegram channel)
3. Study IQ (Burshaya Bano)
4. Kingmakers IAS
5. Kaizen IAS
6. Manuj Jindal
Check this blog it might be of some help https://managementupsc.wordpress.com/
