What I am missing in Midcap Nifty freeze limit?

Hi,

I get freeze qty data from NSE site. The freeze quantity mentioned for Midcap Nifty is 5500 . Today when I placed a sell order for 5500 quantity , I got an error message "quantity should be multiple of 75 " , I am confused, 5500/75 = 73.33

What am I missing here ?

Lot size is 75 so max quantity allowed is 5475 . Ignore 5500

Thak you