NR PRACH cyclic shift for restricted set

Hello Experts

I have doubt regarding PRACH generation cyclic shift for restricted set du value

From spec 38.213 → 6.3.3
In this spec explanation, they have mentioned that q value is the smallest non-negative integer that fulfils (qu)mod LRA=1.
So what is the q value range and whether it is standard constant defined by spec or its design specific ? and what is the value of (qu) here ? and what is qu ?

Please find the attachment of the spec snap shot


#Physical layer