17/8 torino >Parigi non c'è possibilità di prenotazione

Note: it's not clear to me what your entire journey on Monday 17/8 is. I looked from Torino.

The 7:11 Frecciarossa from Torino to Lyon is almost fully booked. Only Executive seats are still available and you can't book those with a pass.

You can however book this Frecciarossa or the TGV at 7:36 from Torino to St-Jean-de-Maurienne Arvan.

From there, you can still get to Lourdes:

St-Jean-de-Maurienne Arvan 11:30 - Montmélian 11:19 (TER, no reservation)

Montmélian 11:49 - Valence TGV 13:33 (TER, no reservation)

Valence TGV 15:11 - Narbonne 17:18 (AVE, mandatory reservation)

Narbonne 18:03 - Toulouse 19:16 (IC, mandatory reservation)

     (There's also a reservation-free TER at 17:27, Toulouse 19:04.)

Toulouse 19:31 - Lourdes 21:34 (IC, optional reservation. I would not book on a Monday evening.)

To book reservations, see:

https://www.seat61.com/interrail-and-eurail-reservations.htm