If I understand the situation correctly, it is as follows:
1. Date of resignation: 15th May 2012
2. Date of relieving: 14th June 2012
3. On leave from: 20th May 2012 to 9th June 2012
4. Will join duty on: 10th June 2012
5. Will get relieved on: 14th June 2012
If these facts are correct, he has given notice for one month and has availed 20 days of leave duly authorized by you.
If he has leave to his credit, then treat this leave with pay, and you must pay his salary. You also received notice from him on 15th May, and you are relieving him on 14th June. That means you cannot deduct any amount towards the notice period as he has served a 30-day notice on you.
If the employee does not have leave to his credit, then treat the period as loss of pay. Even then, he has given you notice for 30 days, and you cannot deduct any amount towards the notice pay.
If he has remained absent and gone without obtaining prior approval, then do not allow him to join duty on 10th June. If you have sent communications stating that he is remaining absent and will be deemed to have gone without notice, then you can deduct notice pay.
But if he has remained absent and if you have allowed him to join back on 10th June, it will be deemed that you have condoned his absence, and no adjustment on the notice period can be made. However, you do not need to pay salary for the period of absence.
Regards,
Sivasankaran