It depends on your grant, and the details can be expensive, so read it before you resign. Typically you keep only what has vested, and unvested options are forfeited. For the vested ones you usually get a limited exercise window after you leave (often 90 days, though some companies offer longer), and if you do not exercise and pay the strike within it, they lapse. Exercising can also trigger tax (in India, perquisite tax on the gap between fair market value and strike), so leaving can mean paying real cash for shares that are still illiquid. Know your vested count, your window, and the tax before you decide, and ask about an extended window if the numbers are large.
A curated summary to orient you, not advice. The resources below are the real value.
2 hand-picked resources, 1 India-specific, 2 link-checked. Pick how you want to dig in.
Why we picked it The most thorough plain-language reference on vesting, cliffs, strike prices, and exercise windows. Read it once and stop being confused by your grant letter.
From Holloway by Holloway
Open holloway.com →Why we picked it The India-specific piece: perquisite tax at exercise, capital gains at sale, and the startup deferral, with worked examples in rupees.
From ClearTax by ClearTax
Open cleartax.in →The same ground, over in Raise money, our Starting Up track.
