Here are some good Jain-friendly boy names starting with S, with simple meanings:

1. Samyak – right, correct, proper (as in Samyak Darshan, Samyak Gyaan, Samyak Charitra)
2. Siddharth – one who has achieved the goal (name of Bhagwan Mahavir in his youth)
3. Shreyans / Shreyansh – one who brings merit, prosperity in dharma
4. Shubham – auspicious, good
5. Sagar – ocean (often used in Jain families)
6. Shantinath – name of the 16th Tirthankar
7. Shantam – peaceful, calm
8. Sumit – good friend, well–mannered
9. Sumedh / Sumedhansh – one with good intellect
10. Suyash – good fame, virtuous success
11. Suhas – pleasant smile
12. Saurabh – fragrance
13. Sagarik – related to the ocean, deep
14. Sanjay – victorious, triumphant
15. Saransh – essence, summary (of truth)
16. Sarthak – meaningful, fulfilled
17. Sachet – conscious, aware
18. Satvik – pure, gentle (in Jain sense: shuddh bhav)
19. Sankalp – firm resolve, vow (like religious vow)
20. Shrut – knowledge from scriptures (Shrut Gyaan)

If you tell me:

• Gotra,
• whether you prefer a purely spiritual/ religious meaning or any good modern name,

I can suggest 3–4 very specific best options for you.