how to trigger a content rule if PloneFormGen's form data is submitted in Plone 4.1
As I recall, PFG submissions don't generate Plone events.  While you could potentially modify PFG (or better yet, contribute enhancements) to add events on form submission, I think the use-case you are describing is probably better realized by building a custom content type to represent your Leave Application Form.  While this is slightly more work than building a PFG form, you can then easily take advantage of workflow, events, content rules, etc.
how to trigger a content rule if PloneFormGen's form  data is submitted in Plone 4.1. eg. I have created a Leave application form for employees. Once the employee submits data, the content rule should send the leave data to his manager. If he approves, final approval should be taken from the General Manager(GM). if the intermediate manager rejects, mail is sent to the employee directly. If approved by GM , mail is sent to employee directly. I want reviewer at 2 or 3 levels with different states.I am unable to define the states and transitions correctly. Can anybody guide?