If you think you want to study after Diploma in Pharmacy, you can study B.Pharmacy or even Pharma D. You can join 2nd B.Pharmacy through lateral entry. Pharma D is a 6 year course after your 12th. But because you already studied, Diploma another 6 years is a long time. But if you consider B.Pharmacy, as you will join 2nd year directly, you will save one year there but if you want to do M.Pharmacy again it will be almost the same duration. So you can think of studying Pharma D. These 2 are the best options after Diploma in Pharmacy if you want to go in the same line.