Does everyone get IPO allotment?

Everyone receives an allotment if an IPO is not fully subscribed or only partially subscribed.

In the case of oversubscription, allocation to everyone is based on the level of oversubscription and the investor category. As per SEBI guidelines, each RII and NII should get the minimum bid lot subject to availability of shares. In case of oversubscription, if the number of applicants is more than the number of allottees to whom the minimum bid lot can be allotted, the allotment happens by draw of lots. In such cases, only the lucky ones will receive the allotment. However, if the number of applicants is less than the number of allottees, the allotment happens on a pro-rata basis. 

In the case of QIBs and other reserved categories, not all investors will receive an allotment if the proportion of investment is very low compared to the oversubscription.