Actually, it may be confusing since the names are similar. Both the hatchbacks were launched in India in 2017 in different months. The base price at the time of launch for Celerio was 4.26 lacs and for Celerio X it was 4.75 lacs.
The Celerio X is a rugged version of Celerio hatchback and is a crossover like version with some extensive crossover-like styling and features, the car is not exactly a crossover car.
Maruti Suzuki Celerio X primarily comes in four variants - VXI, VXI AMT, ZXI, and ZXI AMT, along with option packages for each one of them.
From the rear, the top half of the Celerio X is identical to the regular Celerio, but the lower section gets a new rear bumper with heavy plastic cladding and a diffuser.
I'll write two posts on this forum soon with detailed specifications of both the cars. That should give you a clearer picture.
In short, Celerio and Celerio X are different versions of a particular model and they each have their own trim levels.