Setting a Rule Priority 
You can set priorities which are attributes for rules that govern the order in which rules are added to the firing queue. Firing queue represents a collection of actions of all satisfied rules that are to be fired by the rule engine. The first rule in the firing queue will have the highest priority.
Priorities are assigned as integer values; the value can be within 0 to 1,00,000 (both inclusive) range.
Locate the ruleset, expand the ruleset node, the Rules folder and double-click a rule node.
or
Locate the flow ruleset , expand the flow ruleset node, the Rules folder and double-click a rule node.
Note
You can also expand the Rules folder and choose a rule node.
In the rule editor that appears, click the value next to Priority: and in the drop down menu choose a value or enter a value in the inline textbox.
Save the changes.
Note
You can also do the following to set priorities:
Double-click a ruleset.
In the Overview tab page of the ruleset editor, in the Rules in 'ruleset' table, in the context menu of a rule, choose Set Priority.
In the dialog box that appears, enter the value in the field and choose OK.
Save the changes.