Mr. Krishna, Mr. Vatsa have given valuable advice. Kindly follow it and take the situation and life in positive stride.
Let us look at other perspective.
As a team leader if you have been working late hours { after office hours and if company has not been counting OT or compensatory off etc} then it is but natural that employee shall be attending office late and sensible management should chalk out next day working in a sensible manner and adjust the schedule accordingly.
The situation might have warranted a reprimand or say pay cut of half day or to extend the working hours of the day by the minutes/hours you were late.
There are companies which allow it. The entry is punched by matrix card and if the employee is say late by 1 hour he has to clock 1 hour extra for the day.
The punishment given is severe.
It is like killing a fly with cannon.
Until or unless you were a habitual late comer and did not reform despite advice by seniors, reprimand, warning etc…
Employee in today’s market scenario should keep all record e.g. entry/exit time, leave record, all relevant communications in personal file as you never know when you shall need it and company may become adamant and may not share it although company is custodian of records.
You have mentioned that you have been an excellent performer, and have delivered performance to fetch revenues and profits for the company.
You may apply your rapport, goodwill, and exceptional levels of persuasion, persistence, negotiation, reasoning skills with line management and HR. YOU may not limit yourself to them only and must approach good offices of your appointing authority, MD, Company secretary, and Head-HR and resolve the matter in your favor. Request them to call back the order of termination and let you work and if nothing works request them to call back order of termination and let you tender notice of resignation so that you can look for other employment.
Someone in line management and HR or good offices may rescue you.
This shall be the quickest and easiest solution.
You must submit a carefully structured representation addressed to good offices citing and highlighting your achievements and office hours clocked by you on daily basis and defend your late coming referring to the late hours in office to complete the tasks assigned to you, and request no to award order of punishment and call it back. Even if company does not accede to your requests or maintains a studied silence and the burden of termination on you is severe and you have to approach courts of law/lawful authority this representation shall be a document on record.
The HR in the company may cite its internal company policy which states that reliving letter shall not be issued to terminated employees.
In a given situation employee can approach trade union, and/or invoke the provisions of ID Act, IESO Act, Payment of Wages Act, SE Act as per explanation of employee under the provisions of these enactments or approach civil court. Designation alone does not decide that employee is a workman or not.
It shall be appropriate to approach a competent and experienced service lawyer/labor consultant with copies of all of your documents and give inputs in person and proceed under expert advice of your lawyer. Do not conceal anything from your lawyer. Your lawyer shall evaluate the merits and may opine that you fall within the category of workman. Your lawyer shall arrange for citations and judgments to support your cause.
Company may yield to legal notice of your lawyer or you may have to agitate in the appropriate forum. Company may yield to your demands during conciliation proceedings in o/o ALC or the ALC shall issue reference to Labor Court.
Valuable advice of learned experts/members is sought.