You listed Duration: 7N/8D but your city nights total 9N (3N Madrid, 2N Seville, 2N Barcelona, 2N Paris). Which do you prefer? If you want to keep all four cities, I recommend extending to 9N/10D; if you must keep 7N/8D I will propose a compressed programme (examples below). Also please confirm your arrival time into Madrid on 23 Dec, return flight preference (late 01 Jan or early 02 Jan), and whether you want high-speed trains (AVE/first or standard).
Option A (recommended): follow your suggested nights (3 Madrid / 2 Seville / 2 Barcelona / 2 Paris) — needs 9 nights (arrive 23 Dec, depart 02 Jan). Option B (fits 7N/8D): drop Paris or shorten stays (example: 3 Madrid / 2 Seville / 2 Barcelona = 7N) and fly back to Delhi from Barcelona. Tell me which option to build out with 3 activities per day and transfer times.