I could not verify “Munhani” as a commonly listed Oswal Jain gotra in the standard Oswal gotra references I found. The commonly listed Oswal gotras include names like Gadiya, Bafna, Firodia, Kankariya, Patni, Sangar, Chopda, Lodha, Soni, Dugar, Kothari, Parekh, and others. ( jainknowledge.com)

So, Munhani may be:

• a local family/lineage name,
• a spelling variation,
• or a sub-gotra used in a specific community record. ( jainknowledge.com)

In Jain tradition, gotra is generally a social lineage marker, and the exact list can vary by family and region, so the safest confirmation is from your elders, old marriage records, or community register. ( jainknowledge.com)

If you want, I can also help check whether it may be a variation of another known Oswal gotra name.