Question

what are reserved constituencies?why there is the system of reserved constituencies

Answer 1

The Indian Constitution provides for a special system of reserved constituencies for the weaker sections of the society.
Some constituencies are reserved for people who belong to the Scheduled Castes [SC] and Scheduled Tribes [ST]. In a SC reserved constituency only someone who belongs to the Scheduled Castes can stand for election. Similarly only those belonging to the Scheduled Tribes can contest an election from a constituency reserved for ST. The reserved constituencies help the weaker section to come forward and fight elections, thus guaranteeing the right to equality.

Answer 2

constituencies which are reserved for some cast I mean from where only members of that particular cast can become leader of that area.
there is system of reserved constituencies because in our country some people are poor to bring them up it is used