Both are very different cars. The Tata Altroz diesel makes sense if you are driving long distances and spend long hours on the highway. The Altroz’s relaxed cruising ability, stable high-speed manners, and diesel efficiency and running costs are a better choice.
The Skoda Kylaq has superior engineering, brilliant ride and handing and a very smooth 1.0 TSI engine. The Kylaq is much nicer to drive, more spacious, and overall the better car of the two.