An appeal against the recommendations of the Internal Committee, constituted under provisions of Sexual Harassment of Women at Workplace (Prevention, Prohibition and Redressal) Act, 2013, as mader under provisions of Sections 13,14 and 17 of the Act, may be filed before the Courtor Tribunal in accordance withprovisions of Service Rules applicable to the aggrieved person or where no service Rules exist then without prejudice to the provisions contained in other law, for the time being in force, in such manner, as may be prescribed, within a period of 90 days of the date of recommendations by the Internal Committee.

2) you can take the plea that due process of law was not followed .decision was taken only on basis of oral statement of complainant 

You seem to not have proper legal guidance. Firstly lodge your protest under guidance of a competent advocate and challenge the finding of inquiry by way of suit for declaration and permanent injunction. If you are covered under labour then you can also lodge appeal in labour court. 

- As per law, an employer can terminate its employee , if found guilty of willful insubordination or disobedience; theft, fraud, or dishonesty; willful damage to or loss of employer’s goods; partaking of bribes or any illegal gratification; habitual late attendance; disorderly behavior during working hours; or habitual negligence of work.

- Further, an employer cannot terminate an employee without giving the employee at least 30 days of notice or a salary in lieu of such notice. 

- Further, as per the Industrial Disputes Act, any such employee who has been employed for greater than a year can only be terminated after permission is granted by a suitable government office. Additionally, an employer must provide valid reason for termination and pay a severance amount that is equivalent to 15 days’ average salary for each year of uninterrupted employment.

- Since, the said enquiry was one sided , then you can file a Writ Petition before the High court against the termination.

You can give a properly drafted representation to the Company pointing out the flaws in the internal enquiry and ask it to accept your resignation and convert your position as 'Resigned' instead of 'Terminated" so that there is no stigma on you. 

Section 11(1) of the POSH Act provides that the IC shall proceed to make enquiry in accordance with the provisions of the service rules if the respondent is the employee.

Section 14 of the POSH Act read with Rule 10 of the POSH Rules deals with the punishment for filing false or malicious complaints by the complainant or any other person who is involved in the conspiracy of filing a false or malicious complaint or producing false or misleading documents or evidence.

Section 14 of the POSH Act clarifies that the mere incapability to substantiate a complaint or failure to provide adequate proof does not invite action.

• 
  Anita Suresh Vs Union of India & Others,P (C) 5114/2015: The Hon'ble High Court of Delhi has dismissed a writ petition filed by the complainant and has passed an order directing the petitioner/complainant to pay a fine of INR 50,000 for filing a false complaint and misusing the provisions of the POSH Act.
• 
  Union of India Vs. Reema Srinivasan Iyengar, WP Nos. 10689, 24290 and 4339 of 2019: The Hon'ble High Court of Madras observed that 'Though the Sexual Harassment of Women at Workplace (Prevention, Prohibition and Redressal) Act, 2013 is intended to have equal standing for women in the workplace and to have a cordial workplace in which their dignity and self-respect are protected, it cannot be allowed to be misused by women to harass someone with exaggerated or non-existent allegations.
• The law is clear about the difference between an accusation that is not proved and a complaint that is false or maliciously filed. A complaint filed by the complainant with the knowledge that such a complaint is false or filed with malicious intent should not go unpunished. 

You may pursue the matter legally if you have evidence to prove that the complaint was devoid of merits  and in the absence of any substantial evidence to prove the allegations, it would be considered as malicious, so you are entitled for releif as per law.

You can file the appeal against the said termination 

Dear Client, 

The POSH Act provides that the IC shall proceed to make an inquiry in accordance with the provisions of the service rules if the respondent is an employee.

Section 14 of the POSH Act deals with the punishment for filing false or malicious complaints. This includes complaints that are filed with the knowledge that they are false, or complaints that are filed with malicious intent.

In the case of Anita Suresh v. Union of India & Others, the Hon'ble High Court of Delhi imposed a fine of INR 50,000 on the complainant for filing a false complaint.

In the case of Union of India v. Reema Srinivasan Iyengar, the Hon'ble High Court of Madras observed that the POSH Act should not be misused by women to harass someone with exaggerated or non-existent allegations.

The law is clear that a complaint that is filed with the knowledge that it is false or with malicious intent should not go unpunished. If you have evidence to prove that a complaint was filed without merit, you may pursue the matter legally. In the absence of any substantial evidence to prove the allegations, the complaint would be considered as malicious and you would be entitled to relief as per law.