Source: As worded by Indian Railways, Government of India

If you hold a journey ticket for more than 500 Km, you can break your journey once for two days at any station en route. This facility can be availed only after traveling 500 Km from the starting station. If your ticket is for more than 1000 Km, you will be allowed to break your journey twice.

The day of departure and arrival must be excluded while calculating the number of eligible days for break of journey. And remember to get your ticket endorsed by the Station Manager/Ticket Collector at the station where you intend to break your journey.

Note:

• This facility is not available to passenger traveling by Rajdhani/Shatabdi/Jan Shatabdi Express trains.
• This facility is not permitted short of the station up to which reservation has been done.
• Intention to break journey is to be advised at the time of original booking and not after obtaining reservation.