Gratuity & leaves taxation when company is acquired...

Our company was acquired. Our first company settled entire leave enchasement and Gratuity. My employement with first company was around 3 years only. In full and final statement they gave provisional tax calculation, where they showed 3L exemption for leaves encashment but nil for gratuity. Entire gratuity was taxed. I understand this rule exists for resigning before ~5 yrs period, but in this case company was sold and purchased. My 2 questions are: Leave Encashment is once in lifetime limit or upon every employment resignation ? Is they any way I can save tax on gratuity money paid out to me. It is mentioned as Ex-Gratia in statement.