hello aspirant,
well uttam books are helpful to get good marks in chemistry ,but i suggest one should read entire textbook so that you have a little lnowledge on maximum concepts and there will be higher chances of getting more marks.
"something is better than nothing " ,so atleast you should have a reference on textbook so that whatever the critical length question if appears in exam will makes you to solve and approach it in a simple manner.
well, you can go for reading uttam books too, but it is helpful for you only for a certain extent i.e in cracking only few concepts.
hope you understood,
thank you