Leaves During Notice Period

Hi All,
I have just resigned from my job in an IT company. I have 3 months notice period. I was entitled to 12 casual leaves and 12 privileged leaves. But after resignation all my leaves have been void. The HR says i cant take leaves during notice period.
Recently because of some personal issue i had to take leave for 3 days and i did not got the chance to inform my manager about it.
My manager is very rude and is threatening me.
What legal action can they take against me.
What should i do ? Can anyone please advice me , what will happen next.
Regards
Fresher2014

The notice period may be extended by three more days. Nothing else. Though many companies don't permit leave during notice period, leave on emergency shall be adjusted by extending the notice period by equal number of days of leave. That's all. Taking leave is not a crime, but intimate such absences in advance or on the day.
With best wishes.

Hi Sir,
Thanks for replying. I have read in other forums about leaves during notice period. It says that it is considered as "Loss Of Pay" . What is this "Loss Of Pay". What impact will it have on me ?
Beside that my manager is very rude . He is threatening me to ruin my "Character Certificate".
Can he do that. Will it affect my next job.
Thanks And Regards

Dear Fresher,
Either they extend your notice by leave days or they consider those leaves without any pay or both can happen.
Nothing else can happen.
But make sure from next time that you intimate your manager / HR about the leave in advance or atleast on the same day.
Regards,
Swarna

As mentioned above by members either there will be a deduction of salary for 3 days leave considering it as LOP or extension of Notice Period for further 3days, nothing more can be done. The threatening of ruining your Character Certificate (it should be experience certificate and not character certificate) is vague.