https://en.wikipedia.org/wiki/Mausala_Parva
Congress is non-existent in Assam. No Hindu party in Assam today can take the risk of joining hands with Muslims. AIUDF exists for a reason. If an Assamese mainstream party were willing to accept Muslims, AIUDF wouldn't exist at the first place.
In WB, Congress, CPIM and TMC accept and accommodate Muslims among them. So there is no AIUDF equivalent in WB. In other provinces Congress or some other local party plays similar role. JDU in Bihar. BSP in UP etc.