Bigamy by maharashtra govt employee

That is not bigamy. Bigamy means having two wives at the same time. If you are legally divorced and separated, you are considered unmarried and do not need permission to remarry.

No permission of the Government is required to marry again after a divorce approved by a court of law.

Yes.  A divorced government employee can again remarry without permission from the government, as it will not be considered bigamy. 

No, permission for remarriage is not required after getting divorce.

Remarriage after proper divorce from marriage is not a criminal offence to attract provisions of "bigamy".

Did you discuss with the lawyer engaged for proceeding / contested divorce case ? If so, what is his/her advise ?

He can very well remarry after the previous marriage was dissolved by a decree of divorce granted by a court competent, there is no necessity to obtain permission to get remarried , it is his own will and wish.