How to select only the modified tables in sde versions ?

In the SDE Reader you can specify the Version to read - https://docs.safe.com/fme/html/FME-Form-Documentation/FME-ReadersWriters/geodatabase/GEODATABASE_SDE_reader.htm

By original SDE i’m assuming youre meaning the default version. So you can have one reader reading from default, and another reading from the specific version.

In terms of finding what FCs have been edited in the version, you should be able to construct an SQL query to query the adds/deletes tables to pull that information out (I’d class that as an advanced approach).

There are a couple of similar discussions here:
https://community.esri.com/t5/data-management-questions/see-edits-made-in-a-specific-sde-version-before/m-p/289279#M16549

https://community.esri.com/t5/geodatabase-questions/sql-connection-amp-query-for-versioned-data/td-p/1188705

@hkingsbury Thanks for ur suggestion .

I'm not very familiar with SQL.could you help me in sql query ,if possible .

What SQL query should I use within a feature reader to retrieve obj_id from all tables a and d 

After obtaining obj_id, I have to search all feature classes that also contain this same obj_id .

 then I want to get the data from  matching feature classes  as output.

I’ll be honest, if you’re not confident to create that select statement then that approach is not suitable for you. There are potentially dozens of adds and deletes tables and you’ll need to find the layer ID to find the correct table to look at. Then there are the various states/lineages/versions to look through

Probably the better approach is to look at some of the approaches in the Esri Community