NWAC is a valid Board in India. It is equivalent to CBSE or any other valid Board as it is recognized by AIU.
According to the eligibility criteria of Chitkara University, a student must complete there 10+2 from a recognized board and percentage criteria can be varied according to the course in order to take up the admission in the university.
Therefore no need to worry about, your kid will definitely eligible to take up the admission in Chitkara University if she completed her schooling through NWAC Board.