Guaranteed Surrender Value is the regulatory floor for what an insurer must return on early exit. The percentage is set by IRDAI and rises with policy year — it starts at 30% of premiums paid (after year 2 or 3) and climbs to ~90% near the end of the policy term.
GSV is calculated only on premiums paid for the basic policy, excluding the first year's premium and any rider premiums. Vested bonuses are surrendered separately at a discount, using the insurer-published Surrender Value Factor (SVF) for vested bonuses.