Hello aspirant,

No coaching is not compulsory for cracking ipm and bba entrance exam if your bapsic concepts of mathematics are clear. You can easily prepare with self study at home by refering to some books. Also there are many free videos available on youTube for concept clarity so there's no need of coaching. But yes I'll recommend you to purchase test series for practice. You can refer to following link for your preparation guidelines:
https://www.google.com/amp/s/bschool.careers360.com/articles/ipmat-syllabus/amp
Good luck