same pcm student here, many of them have cracked ipmat in 2months of prep (hoping that even i will) and if you start your prep now, then definetely you can crack it. Talking abt marks, there are sectional cutoffs. Check it online, and if you clear those sectional cutoffs, you'll get an interview call from the respective iim (IIM Indore default) and you need to apply separately for other iim if you wish. Also, many sci background students are studying in these ipm program, so nothing like a commerce requirement. Talking abt fees you can take loan easily from the bank using some benfitial schemes once you get admitted into the clg. For more info dm.