Hi @PrernaC5

Create one Edit Validated rule and paste the below code into it.

Could you please check the below code and try once?

if (theValue.toString().length() == 0) {
    return true;
}

int iInput;

try 
{
    iInput = Integer.parseInt(theValue.toString());
}
catch (java.lang.NumberFormatException ex) 
{
    return false;
}

if (iInput < 25) 
{
    theProperty.addMessage("Age Must be 25 and above");
    return false;
  //You can write your own message in side double quotes
}

return true;

and as soon as you enter the age below 25, it throws an error.

I hope this will help you,

Thanks,

Ashok

@PrernaC5

if you have date field to capture DOB, try creating constraints rule for it to show your validation. 

Or you can create a validate rule and add to the flow action of that section.