See nowadays, most of the application for admission are submitted online. So yeah! from a general perspective you have to apply online for the admission to different colleges. Now depending on your college, you may have to appear any entrance or you can directly provided admission on the basis of your merit marks of your previously qualified examination. For entrance you have to apply in counselling and based on your rank you will be provided admission. For merit marks case you need to visit the official website of the college and apply with all the details. The college will release 1st list, 2nd list etc and on the basis of the vacancies available you will be allotted seats. Now for both the cases after your online admission i.e., payment of fees, you have to visit the college on the prescribed for document verification and if all the documents is ok and matches with the online application, then your admission to the college will be accepted.

For D.pharm colleges you may visit the link below:

https://pharmacy.careers360.com/colleges/list-of-diploma-pharmacy-colleges-in-india

I hope this answer helps. All the very best for your future endeavors!