I have recently found out that the busses with the number 221 and 333 are those that bring me to the nearest metro station. So actually I again asked different persons getting different answers until I met a guy who told me the numbers in relatively good English. Again it was a very long trip from my place to Delhi City Centre as I was facing a lot of traffic jams - it took me at least 2 1/2 hours to finally reach my destination.