WHIP in Indian Parliament

WHIP is that mechanism and instrument by which political parties in Indian Parliament practically exercise their influence by consolidating their numbers in the Parliament. It is not impossible that each and every member elected to Lok Sabha or Rajya Sabha possesses a different view from that of the leadership of that political party and in that case at the time of voting or while supporting a particular bill he may deviate from his party's stand. So this tool of WHIP ensures that any member of a political party does not contravenes the stand taken by his political party on the floor of the house. In order to understand what exactly WHIP means and how WHIP works I am reproducing the two below paragraphs from M Laxmikanth for your reference.

Though the offices of the leader of the House and the leader of the Opposition are not mentioned in the Constitution of India,they are mentioned in the rules of the House and Parliamentary Statute respectively. The office of 'WHIP', on the other hand, is mentioned neither in the Constitution of India nor in the Rules of the House nor in a Parliamentary Statute. It is based on the conventions of the parliamentary government.

Every Political Party, whether ruling or opposition has its own WHIP in the Parliament. He is appointed by the political party to serve as an assistant floor leader. He is charged with the responsibility of ensuring the attendance of his party members in large numbers and securing their support in favour of or against a particular issue. He regulates and monitors their behaviour in Parliament. The members are supposed to follow the directives given by the WHIP otherwise against  them disciplinary action can be initiated.