An NFO scheme, or New Fund Offer, is a mutual fund launched by an asset management company to raise capital from investors. To invest in NFO scheme online, use platforms like mutual fund websites or apps, where you can register, complete KYC, and select the NFO. After reviewing the offer document, invest through net banking or UPI, ensuring timely subscription within the open period. This digital process simplifies access to new investment opportunities in the NFO scheme.