Since you are able to purchase a new Kia Seltos or Carens Clavis EV, we would suggest you not look at a used Tata Harrier or XUV700, as these are quite close in size, performance and features. If you are buying used, it makes sense to get something from two segments above.
As to your query about a diesel or electric, yes, both are not likely to have a high resale value. There's certainly a cloud over diesel's long term future, and the pre-owned EV market is too nascent to judge future potential.
We would, however, recommend the EV as you will be keeping your car for about 10 years, and in that time with your running you would save on fuel bills. Between the Hyundai Creta electric and the Clavis EV, we would suggest the Kia as it's very similar mechanically. But also offers you the benefit of the third row of seats, which is quite spacious and usable.

