Hi @rahul_521,
You could do it as follows:
In the survey tab of your xlsform:
In the choices tab of your xlsform:
Data entry screen as seen in Enekto: (when a wrong entry is made)
Data entry screen as seen in Enekto: (when a correct entry is made)
Data entry screen as seen in Enekto: (when a correct entry is made)
Reference xlsform:
2020 08 21 Constraint (If-Statement).xlsx (11.1 KB)
Have a great day!