Hi @Bijender 

Try the below script.

(function executeRule(current, previous /*null when async*/ ) {
    var slaGR = new GlideRecord('task_sla');
    slaGR.addQuery('task', current.sys_id);
    slaGR.addEncodedQuery('business_percentage<100^sla.name=P3 resolution'); // CHANGE THE SLA NAME AS REQUIRED
    slaGR.query();
    if (slaGR.next()) {
        current.u_sla_cal = 'Yes';
    } else {
        current.u_sla_cal = 'No';
    }

})(current, previous);

Regards,
Siva