• Eligibilty for contesting in union election

In our company 3 year once they are conducting union election.This is AIDEU Approved by govt union.
1.Is there any rules and regulations are there for eligibility for contesting a person for office bearers?
2.If a person is having only 6 month service left means,whether that person can contest as a office bearer post or what?
3.If he is elegible then after 6 month of his retirements what will happen?
4.because of this single person why should again go for re-election?
please tell me with some proper rules is been laid by any court or Govt authority?