10600 call is out of money call …they get affected less on normal movement, the more out of money you go the lesser it gets affected by underline movement.
Look at at the money call’s yesterdays price and todays they are most changed,
for more precise technical clarity read chapter on this in zerodha varsity.
It happened due to significant drop in Volatility(as exit polls suggested that BJP may win) after you put on the long position. This is a classic case when Volatility overpowers Delta (underlying price move in your favour) and thus nullifies gains. Also, since the Call was OTM its Delta was much lower (what goldb has mentioned above) hence weaker gains from underlying price movement. I have only briefly explained the phenomenon to keep it short, if you want further detailed explanation of what exactly happened then let me know, I will extend the explanation. This is similar to the situation when traders buy a Long straddle (Buy an ATM PUT and an ATM CALL) before an event expecting a move in either direction to yield profit after the event, but end up in losses despite a good move in the underlying.
Not just significant drop in VIX, actually initial 30 mins were extremely volatile & Nifty crashed to around 300 points in a matter of seconds creating a panic.
During first hour, the 10600 call would have lost 70% of premium. And later the markets bounced back gradually so yes VIX also declined considerably & though markets returned back in green but the fall was sudden but rise didn’t happen immediately like a sudden spike.