i'd rather have sooraj turn positive than param.
in my personal opinion rapist are sexual predators like pedophiles and they don't "change" just like that. That's why so many of them are recidivists even after they get out of jail.
So showing param turn positve after he attempted to rape Ishita will be a bad message to society. It'll show that you can't trust a recidivist rapist (sarika, ishita, ... i don't know who else he tried to molest), when in reality it's not a case.
I'm all for redeeming character but there is a limit. A murderer can redeem but he has to do his 20+ years jail sentence none the less (another thing that is commonly avoided in indian soaps).