As per the leave rules/regualtions:
Relevant provisions of CCS Leave Rules that covers eligibility for Earned Leave while in resignation notice period are Rule 9 (1) and Rule 39.
Rule 9 (1) CCS Leave Rules provides as follows
“Except as provided in Rule 39 and this rule, any claim to leave to the credit of a Government servant, who is dismissed or removed or who resigns from Government service, ceases from the date of such dismissal or removal or resignation.”
It is very clear as per this Rule 9(1) of CCS Leave Rules that after resignation from government service, leave at credit ceases to exist from the date of resignation.
The ineligibility availing earned leave on resignation is further confirmed by Rule 39 (1d) to the extent that no leave can be granted by the authorties concerned when a central Government Emplyee applied for Earned leave beyond the date of resignation from Government Service.
However, Rule 39 (6) (ii) of CCS Leave Rules provides that if a Government Servant resigns or quits Government Service, he may be granted, suo motu, by the authority competent to grant leave, cash equivalent in respect of earned leave at his credit on the date of cessation of service, to the extent of half of such leave at his credit, subject to a maximum of 150 days.
From the above rules it is clear that you can avail earned leave in lieu of the notice period if you have earned leave to your credit.
Your all the questions are answered accordingly as above.