According to the Noise Pollution (Regulation and Control) Rules in India, the noise level in educational institutions during night time (10 pm to 6 am) must not exceed

In silence zones such as educational institutions the night-time noise limit is 40 decibels.

The 35 decibel value falls below the prescribed silence-zone night limit.

The 45 decibel value applies to residential areas at night, not silence zones.

The 50 decibel value is the daytime limit for a silence zone.

Night time here runs from 10 pm to 6 am under these rules.

Silence zones also extend to areas near hospitals and courts.