Step 1: Transform your data into a list
The Rules Data Transforms module (DEV version only!) may help to solve your issue. It supports the transformation of a string of values separated by some separator (such as a comma) into a list. So you should be able to transform your "multiple mobile number with comma separated" (as in your question) into a list. There doesn't seem to be any documentation available about this module, except:
Step 2: Typical list processing with Rules
After you succeeded in transforming your mobile numbers into a list, you should be able to perform the typical list processing using Rules. If you're not familiar with that, have a look at the tutorial titled "Lists and loops". Starting from about 7:00, it shows how in a Rules Action you can access the 1st, or 2nd, or ... value of a multiple value field, provided you also included a Rules Condition like "Content is of type" (related to the multi value field). If you consider the
field_tags in this video as the equivalent of your field containing the mobile numbers, it's pretty similar to your case. Have a look at this video from the beginning to understand how this rule works.
Specific to your case, all you'd have to do is to adapt the Rules Action in the rule you already have, i.e. by adding an appropriate loop, and then add a action for each list item in that loop (which is similar to the Rules Action you already have).