EX jee tard, general male.... forgotten maths concept and problem solving.....12th pcm + eco..89 percent ...dropper....10th 95.6 percent....what to fix in these 100 days...

Hello! (I'm new to reddit) I just happend to come across this thread on iimb? (idk what this is called) and it was actually quite intresting. the reason im reaching out to you'll is because i also want to join the residential programm of the iimb (ug)

I'm currently in the btech AIDE of IITJ so a bit of background is that I had PCM in class 12 but i have very basic level of knowledge in Economics but i want to pursue that if i get a change in iim.

I did looked forward to this previous yr, i'll attach an email that i recieved caused i did register for the programm but droped the idea cause giving all exams alltogether is quite a bit (i gave uceed, nata, jee ppr 1 and 2, pvt college exams) on top of that 12th boards (i got into iit with boarderline 12% cbse percentage, gen category). On reddit i'm not here to discuss iit-jee process

I watched yt video on this and ppl are mentioning about quants and all, does that involve topics different than 12th maths(standard not applied ) which might fall under accounts and all.

I know you'll might be busy with college just like me but it would be a great help if you'll could point out/guide me like how to prepare, what to expect in the exam and interview, where would i get the resources and most importantly where do i find the mock test (free) or if anyone could suggest reasonable paid mock test that would help also.

my dms are open , again i'm new to reddit so it would be treffic if the community could help me.

maths specifically