Surrender Value is what you get back if you terminate the policy before its scheduled maturity. For traditional endowment policies it is the higher of two amounts: the Guaranteed Surrender Value (GSV), set by IRDAI rules, and the Special Surrender Value (SSV), set by the insurer based on its current valuation.
No Surrender Value is payable in the first 2–3 years (depending on the policy). After that, both GSV and SSV grow with each premium paid, but recovering 100% of paid premiums typically requires holding the policy for 8–12 years.