Anchor Investor

An Anchor Investor is the first investor in any round, that provides subsequent investors a degree of confidence. Until you have the first investor, no body wants to be the first one to take a bite. Once you have the first investors, others feel assurance that others are willing to invest.

Source: https://www.answers.com/Q/What_is_anchor_investors

an anchor investor is a QIB who makes an application of Rs10 crore or more in an IPO

an anchor investors means a QIB investors. .
i.e. a QIB who will make an application more than equal to rs 10cr in an IPO such investors known as ANCHOR INVESTOR

Anchor Investors are the first line investors in the Book building process of the company. They quote a fixed price for the shares even before the bidding process starts and are bound to purchase the shares at the price identified by them even if the shares are subscribed at a lesser value, and on the contrary shall pay the remaining amount if the bidding price is determined at a higher value. They get preference in the allotment of shares for such treatment and risk taken.