You cannot edit these within Aximmetry.
The reason is that the transformation system and/or the rotation order can be very different in these systems, therefore they cannot be simply described in the Aximmetry-specific position-rotation-scale model.

So please always do the editing of these animations in your 3D software. When you export them, Aximmetry will automatically reimport them right away, so it's fairly easy to work this way.

Alternatively use Aximmetry's internal Sequencer right from the beginning.

But we need to do interactive animation like in/loop and out using markers not only linear animation only.

any suggestions for doing this? 

Yes, you can freely add markers to the Sequencer automatically created by the importer.
Also you are free to replace the automatic Sequencer with an InOut / InLoopOut sequencer (or more of them, if you want to control different objects individually).

The only inconvinience that you won't see the actual keys within Sequence Editor, but everything else works normally.