Suppose it takes 1200 euros to visit Suriname. and I am from India. Now first i converted 1200 euros to inr which came as 93689 rupees . Then just out of curiosity, I tried converting 1200 euros to usd first and then I converted that amount of usd to inr. And i found it came back to same 93689 rupees. Like, it could happen in this way that euros to usd rate is something different so that either I get a higher rupee figure or a lower one. So How come there is the same amount, no matter I convert it directly from eur to inr or indirectly eur-usd-inr ???
If it were different, then this would produce something called "arbitrage". When arbitrage appears, it generally disappears rather quickly as people take advantage of it. For instance, suppose that Eur -> USD -> Inr gave a better rate than Eur -> Inr. Then what would happen is that people would use Eur to buy USD, use it to buy Inr, then use the Inr to buy Eur. They could then cycle through this again and again, making more and more money. This would drive up the demand for USD in Eur and Inr in USD, making those prices higher, until eventually the arbitrage disappears.
It's complicated a bit by transaction costs (I would expect that if you do Eur -> USD -> Inr you'll get a slightly worse rate than if you do Eur -> Inr, because you'll be paying exchange fees twice), but without fees, every path between two currencies should end up with the same rate.