You may change trains as often as you like and take as many trains as you like even in your country of residence. So that's ok.

(You just do need to get the mandatory reservations for e.g. TGVs in France before; but I assume you do know.)

Thank you for the response.

Just for better clarification:

For the inbound, I have to make a stop at Strasbourg before entering to Paris again, as there are no direct trains from Basel (Swiss) to the specific Paris station I want to go.

In the rail planner app - when I search for Basel to Paris it showed this connection with one transfer - but the gap between the transfer is short (20 mins).

Since I have heard trains could be late. So I am planning to first go from Basel to Strasbourg and then take another train after 1 hr from Strasbourg to Paris.

So according to what you said above - it wont be counted as two inbound journeys?

It's totally fine and you should indeed plan with some margin. On such travel day you can take 1, 2 or 20 trains in France it doesn't matter.

Btw you should be able to get free TGV reservations if you go to a SNCF ticket counter: special offer for French residents -> billet parcours d'approche or something similar.

I am not sure if I am a resident. I have a job in France with a residence permit for 2 years. will this is ok?

If so, can I make the free reservation anytime before for the inbound journey or only at the Strasbourg station?

Should be fine yes. Not all SNCF are aware of that offer though…

Feel free to ask in advance at a counter, if not book online. You definitely shouldn't wait until the day as TGVs often sell out (the Strasbourg route is quite popular).