Jiofiber prepaid vs postpaid

I have been using JioFiber prepaid since the lockdown and have been opting for the ₹999 plan only for OTTs. I came across postpaid plans that offer OTTs for less. What are the main differences? Can I switch to a postpaid plan, try it, and then opt back to prepaid if I don't like it? I have seen OTT plans for ₹699 or so that also include YouTube Premium.