Here are some Jain-friendly, relatively unique baby boy names starting with “D” (and easy to pronounce):

1. Dharam / Dharma – righteousness, virtue
2. Dharamraj – king of righteousness
3. Dhaval – pure, white, calm
4. Dheer / Dhir – patient, courageous, steady
5. Dhiraj – patience, inner calm
6. Dhiram – calm, composed
7. Dhyanu (Dhyana) – meditation, contemplation
8. Dipesh – lord of light; enlightenment
9. Dipankara – one who brings light
10. Dhanesh – lord of (spiritual) wealth, virtues
11. Dharmik – righteous, follower of dharma
12. Dvij (Dwij) – “twice-born”, spiritually awakened seeker

These names are suitable for both Digambar and Shwetambar Jains; there’s no major difference in meaning, only in local pronunciation or spelling.

You can read a related answer here