CAT

The main exam is CAT or XAT along with WBJEMAT exam. The last one is mandatory.

Yes the best score of CAT, XAT & CMAT will be considered for admission.

According to GMAC, 140 to 170 will be a safe score to get admission in LM Thappar B-school. However, the cutoffs may vary every year.

You need to allocate 3 to 4 hours daily. You must study with full concentration. You must revise the basic concepts of mathematics, verbal needs to be practiced regularly and DI/LR needs focus, concentration and patience.

The syllabus is more or less the same. The bulk of the syllabus for banking and CAT exams consists of:
1. Quantitative aptitude.
2. Logical reasoning
3. Data interpretation.
4. Verbal reasoning.
5. Critical reasoning.
6. Verbal aptitude.
7. Reading comprehension.
To know more about the IBPS PO, you can visit the below mentioned link:
https://www.eduncle.com/ibps-po-recruitment-exam
These are the common areas in these two exams. The extra bit in some of the banking exams is:
1. General awareness.
2. Computer awareness.
3. Banking awareness.
4. Marketing aptitude.

It is a very low score to get a decent college. I would suggest you to appear for CMAT exam as well.

IIT KGP provides admission through CAT. The percentile requirement is higher for general category an approximate of 97-99. Then you will receive a call from the college for further rounds.
Best wishes!

You can start preparing in your final year or you can start from your second year.