We have many to many relationship and when i select a attribute then i get duplicates , any idea why we get this?

Many to many relationships do not affect the cardinality of the dimension attributes so that is not the problem here. I suspect that you have a type 2 dimension at this attribute has it's key property linked to the surrogate key column and the name column is linked to a name column.

The fix is probably to create 2 attributes - one with it's key column to the "Proid Owner Type ID" (this is the column used to join to your measure groups) and another with the key and name linked to "Proid Owner Type Name" to give you a distinct list of names.