Answer

Yes — in the area that is now Bangladesh, there was a Jain presence before 1947, but it appears to have been small and limited, not a large widespread community. Banglapedia says Bengal was an early center of Jainism, that Jainism was alive in places such as Pundravardhana and Samatata, and that later in the region Jain followers were “hardly met.” ( en.banglapedia.org)

Explanation

If by “Jain community” you mean a local, settled population in the modern sense, the historical evidence points more to small Jain merchant groups and families than to a large indigenous Jain majority. Banglapedia notes that Marwari traders in British-period Dhaka and other East Bengal towns included both Hindu and Jain groups, and that many Jains who settled in Bengal were Śvetāmbara. It also records Marwari business centers in Dhaka, Chittagong, Naogaon, and Mymensingh. ( en.banglapedia.org)

Spiritual Understanding

From a Jain perspective, this shows that Jain Dharma did reach and influence Bengal deeply in earlier centuries, even though its living community in the region became quite small over time. ( en.banglapedia.org)

Takeaway

So the careful answer is: yes, there was a Jain presence before 1947 in what is now Bangladesh, but it was small and mainly connected with merchant communities rather than a large local Jain population. ( en.banglapedia.org)