I may add,
Are you a fresher or your firm is very young not to have your Conduct & Disciplinary Rules or SO in vogue. To put it simple - the basic aspects are common to any type of entities and employee. These are -
1. Employee and Employer relationship
2. There shall be a competent/designated authority duly named as Disciplinary Authority, Appellate Authority.
3. You should have well defined, documented list of what are to be considered as 'Indiscipline' and what rules and procedures are to be adopted for trying the employees at default.
4. There shall be alleged indiscipline, properly documented by the parties involved and it is forwarded by the concerned to the designated authorities for appropriate action.
5. There shall be a preliminary enquiry and a report thereon to find out whether there is a 'prima facie' evidence to show 'indiscipline' to proceed further supported by documents & witnesses.
6. Examine whether the alleged charges of trivial, which can be pardoned or serious and to be tried further.
7. To arrange issue a formal 'call for explanation' to obtain the submission of the employee concerned.
8. The DA should consider the submission and take a view whether the 'indiscipline' has been committed willfully or unknowingly/unintentional and whether could be closed with very minor punishment or should be fit to be taken/proceeded further.
9. The DA prepares the formal 'charge sheet' wherever the submission to 'show cause notice' not satisfactory and ask for the detailed reply to every point contained in the SCN.
10. Upon receipt of reply to SCN the DA fixes advance date for recording statements of accused, the witnesses, examination of docs, and Presenting Officers. And gives time for submission of docs. & witnesses to defend and in proof.
11. Presentation by the Union representatives on behalf of accused is permissible where all the parties are to be present.
12. After recording proceedings on various dates the DA corroborate the evidences, arguments & docs. and come to conclusion and gives his verdict either for or against.
If you don't have SO prescribing the procedures what models made available in citeHR may be followed.