Allotment of Shares

How shares are allotted in IPO’s to retail investors and HNI’s ?

Pls go over the following for help on this topic:

https://www.nseindia.com/products/content/equities/ipos/ipos.htm

https://www.quora.com/Are-there-any-rules-which-govern-the-IPO-allotment-for-retail-individual-buyers-in-India

I check in the chittorgarh website . it provide details once allotment is done