Yes an individual investor can apply in Non Institutional Investors category of an IPO.
"Individual investors, NRI's, companies, trusts etc who bid for more then Rs 1 lakhs are known as Non-institutional bidders. They need not to register with SEBI like RII's. Non-institutional bidders have an allocation of 15% of shares of the total issue size in Book Build IPO's."
There are few advantages and disadvantages for retail investor to apply under non-institutional category of the IPO.
Advantage is that there is no upper cap on application amount. An individual investor can bid for any amount in this category where there is limit of Rs 100'000 in Retail category.
Disadvantage is that only 15% of total shares are part of Non Institutional Investors category. The Retail Individual Investors (RIIs) category has 35% of total shares available for investors. This means that Non Institutional category oversubscribed heavily and chances of getting allotment are much lesser.