Learned follower MmsMnk has very rightly suggested, and I agree with his views in totality. The only thing I would like to add is that advance leave or pro-rata leave cannot be granted to any employee if the company's policies do not permit it. This would create unnecessary demand for advance leave in all such cases, making control very difficult for an HR Manager. If denied to others, this could raise questions from law enforcement agencies, to which there would be no legitimate answer.
To avoid future complications, it is best to stick to the rules and policies currently in force. We can offer help by allowing the concerned employee to take leave without pay if they choose to do so. Otherwise, leave should be categorically denied without any deviation.
Best wishes,
AK Jain
HR Personnel
NCL, CIL