1. you have resigned and same accepted by them, so no need get worry.
2. You may prove mail as proof of evidence and acceptance from the management.
3. Ask them When they had the problem with your relieve then y they are accepted the resignation.
4. Take the printout copy of their acceptance by mail and same can send by courier to the advocate with explanation of his letter.
You haven't mentioned the time gap between when you resigned & left and this Notice.
If it's high--maybe over a couple of months--then you may as well mention that aspect too in your reply to the Notice.
However, I would LIKE TO VIEW THIS IN A DIFFERENT WAY--other than the way Aditya mentioned [replying to the Notice].
For all I know, this COULD be a ruse to see what cards you hold in your hands IF they go legal. In which case, you would only be opening yourself to more legal headache [NOT trouble].
Suggest consult a lawyer before replying legally. Quite often, what's very apparent & logical from a layman's perspective COULD be a big mistake legally.
There also SEEM to be some gaps in what you mentioned--I only HOPE you are not hiding some facts of the case.
For eg., you worked there for 19 months & you mentioned you get salaries after 3 months. Is this regular right from 19 months? Or has this been a recent situation? And is this common to ALL employees?
You have also not mentioned your designation.
The mention of 30 L by the advocate sounds preposterous--from one angle. But from ANOTHER angle, it leads to suggest that there's something else to the whole issue.
Thank you for your attention. Please find below the reply which you asked as given point wise.
* I have resigned on 28th Feb 2014 and they asked me to leave on 1st of March 2014.
* I have received this notice on 29th August 2014.
* I joined there on 17/7/2012 as a Manager Operations and they promoted me as a Branch Manager with the salary hike of 1.2 L per annum. I joined there with INR 45000/ per month and after appraisal it was INR 55000/ per month.
* Yes,every staff gets salary late over there ,even they also sent the same letter so some managers as well.
I hope the above is in order,feel free to ask with me anything.
I still suggest that after giving reply to legal notice try to come to an amicable solution by discussing the issue with the management. all the best.