Where are you based Raj' your English is a little hard to decifer, mcb's 1,2,4,6,10,16,20,25,32,40/45,50 and 63, these are the extent of values but not all brands have all the ratings, MCCB's can come with an adjustable rating but again not all have this feature and they have ratings up into the many 1000's of amps.
What is the load your protecting here? Adding this to your previous thread i feel your stepping into an area you have little understanding in.
What is your Electrical background so we can tailor our answers to suit?