Differentiate between Upper price and cut-off price of Book-building issue?

There are two types: Fixed Price Issue or Book Building Issue. Fixed Price is the type that has a fixed price. Book Building gives you a range of prices within which to bid.

Retail investors can bid at a cut-off price, which means they are willing to pay whatever the company decides at closing of the IPO.

The cut-off price will usually be the same as the upper level price. They don't have to be the same every time.