Answer

Yes, Mehta surname is found among Shwetambar Jain families in many regions.

However, from only the details:

• Surname: Dheladiya Mehta
• Native place: Gadh Siwana

I cannot confirm with certainty that the family is definitely Shwetambar Jain, because surname and native place alone are not enough to establish panth/sampraday.

Explanation

In Jain society, panth or tradition is usually confirmed through family tradition, such as:

• Which Jain temple or upashray the family follows
• Whether the family follows Shwetambar Murtipujak, Sthanakvasi, Terapanthi, or another tradition
• Family guru-parampara or sangh connection
• Old family records, marriage records, or community records
• Traditions followed during Paryushan, Samayik, Pratikraman, Diksha sambandh, etc.

Spiritual Understanding

In Jain Dharma, identity is respected, but the deeper focus is on:

• Right faith
• Right knowledge
• Right conduct
• Ahimsa, Satya, Aparigraha, and self-purification

Takeaway

Your details may indicate a Jain family background, and Mehta can be associated with Shwetambar Jains, but for confirmation, it is best to check with elders of the family, your native-place Jain sangh, or family religious records.