There are two ways you can do this :
Parcel booking and Luggage booking
Parcel booking : I am not sure how they (Indian railways) came up with those terms but those are the two ways you can do this. Parcel booking can be done by going to your nearest station and filling a parcel form and you leave your goods there and you can expect it to reach your destination within five to seven days. To receive your goods you have to go to the destination railways station and present your receipt. You wont be traveling on the same train and it costs a bit extra as compared to luggage booking. Another important thing to note is parcel bookings can only be done during office hours on working days.
Luggage booking : This is what you want as you are planning to travel with your luggage on the same train. You should ideally reach the railway station at least three hours before the train departure (better to have time on your side). There are security checks and those guys are "slow" so keep that in mind.Recent Uri attack may have heightened security.
How to book your luggage:
Requirements - Government issued ID, train ticket and reservation for the same train as you want to book luggage in.
Procedure to book luggage - Go to the station a day before your journey and fill out the luggage booking form. The reason you should go a day before is to make sure you have a booking in case the brake van gets filled up and you wont have any options left.
On the day of your journey reach the station at least three hours before of more. Go to the parcel office and present your booking receipt and they will transport your luggage to the platform for you. They will also load your luggage when train is ready.
On reaching the destination you would need to "run" to the parcel office and present your receipt and they will then offload your luggage.Some stations are proactive and you wont have to worry about it but my advise is to get to the parcel counter as soon as you can. Parcel office will also issue you a gate pass which you would need to present at the gate while exiting with your luggage.