Suppose I buy 1 bitcoin on unocoin at 174,000. Now I see that the selling price on unocoin is 160,000 and selling price on coinsecure is 170,100. So can I sell my bitcoin on coinsecure directly?
Assuming these are exchanges with their own wallets, you would need to first transfer your coins to your wallet on that exchange, while of course paying the required fees.. Using the numbers in your example, it would seem far more prudent to sit on your funds until you can sell at a gain (you don't lose until you sell).
Regardless, yes, you can game different exchanges. The risks are (IMO)
1) you pay a fee 2) you hope that the price doesn't drop on your intended target during your pending transaction.