The helpline (011-2735 2525) was announced by Education Minister Manish Sisodia last month. It will enable aggrieved parents to contact the office of the education minister about nursery admission-related problems.
Nursery admissions are set to begin on Wednesday.
"Why are Delhi schools resistant to being transparent? They should not have approached the high court," Kejriwal said.
He said the schools were "charitable societies" and their motive should not be to earn profits.
Kejriwal also launched a web application, www.edudel.nic.in, which will facilitate pre-primary admission in recognised private schools.
"Leading a comfortable life is the dream of a common man, and education is the basis of that dream. It is (helpline) a step in materialising that dream," Sisodia said.
The application will let parents find nearby schools by keying in their address or location.
Sisodia added that the application and the helpline have been launched to bring transparency in the education system in Delhi.
"Parents can register their complaints regarding any school by calling the helpline. Their grievances would be addressed in three working days," he said.