Answer

In a Jain home mandir, it is generally best to keep only Jain idols or images, such as Simandhar Swami or other Tirthankars.

Keeping other Hindu gods along with a Jain Tirthankar in the same mandir is usually not recommended in a strict Jain setting.

For kuldevi, if your family traditionally reveres her, it is better to keep her separately, not mixed in the same Jain mandir.

Explanation

A Jain mandir is meant to support Jain bhakti, meditation, and remembrance of the Tirthankars’ qualities:

• Vairagya
• Ahimsa
• Samata
• Self-purification

Simandhar Swami is a Jain Tirthankar, so He belongs fully in a Jain mandir.

Other deities, including kuldevi, come from different worship traditions. Mixing them in one mandir can blur the devotional focus of the Jain shrine. That is why many Jain families keep:

• one space for Jain worship
• another space for kuldevi or family tradition, if needed

Spiritual Understanding

In Jain Dharma, the mandir should help the mind become:

• शांत
• एकाग्र
• निर्मल

A clean and focused Jain mandir supports reverence for the Jina path without confusion. If you want to follow Jain tradition sincerely, keeping the mandir dedicated to Jain devta-tirthankar bhakti is the most appropriate approach.

Takeaway

If you want to follow Jain tradition properly:

• Keep Simandhar Swami in the Jain mandir
• Do not mix other Hindu gods in the same mandir
• Keep kuldevi separately if your family tradition requires it

If you want, I can also tell you the ideal setup of a Jain home mandir according to Jain tradition.