Hi Rudra ,
There are a couple ways the product will let you achieve this, but the most common way is to define multiple sources for your Incorta table definition. The approach works best when DB1.T1 and DB2.T2 have the same columns, as this approach requires that the results coming from the different table source defintions agree on column name and type. Aliases can be used in the defining SQL SELECT statements to subtle adjustments to force agreement. There are other ways to do this that get slightly more complex (like bringing in DB1.T1 & DB2.T2 as-is as Incorta tables and then defining a Materialize View on top of them to build a unified unioned table). See screenshot.