>If you are born into the lowest level, can you attend school, enter the business world and suceed to attain a very high level in business and society?

Yes, not a problem now. In fact the govt. since long has introduced reservation system for Scheduled Caste and Tribes where govt. institutions have kept seats just for the SC/ST people (now isn't that promoting caste system for votes). If I am not mistaken even the high quality institutions like IIT have it. Thus if a person belongs to SC/ST and doing so-so can attend such institutions if the seats are available. I have heard of a case or two where a person belonging to a higher caste did the required affidavits and switched to SC/ST to take advantage of the subsidies and benefits available to SC/ST :)