National Investment and Infrastructure Fund (NIIF) Tuesday announced an investment of Rs 660 crore in HDFC Capital's real estate platform that finances mid-income and affordable housing projects. The NIIF will invest in HDFC Capital Affordable Real Estate 2 (H-CARE 2), an investment platform, managed by HDFC Capital Advisors, a wholly owned subsidiary of HDFC Ltd, the company said in a statement. NIIF will join a wholly-owned subsidiary of the Abu Dhabi Investment Authority (ADIA) as an investor in H-CARE 2, it added.