Legal issues - employee left after 3 months - threatening the company that you must provide three months work experience letter

Hello Seniors, One of my friend need your help. He is fresher HR working newly in organization need your help.
He issued offer letter to candidate just mentioned joining date and retention amount that cant claim if left before six months. They appointed candidate during interview company told that whenever require he need to stay half an hour to an hour that time he said yes agree and all.
Now that fresher said No to the company after three months that not able to stay if any urgent work. Now he left job & one of his relative threatening the company that you must provide three months work experience letter and they will go to the labour for minimum wages and all.
Now my friend not issued any appointment letter or not mentioned any notice period or not any bond amount mentioned in offer letter but one sentence mentioned that -You will serve a bond with us for a minimum period of 6 months from the date of your joining.
Now my HR friend need your help what employee can do in this matter? This also new for my experience.
Candidate was fresher and company provide him the opportunity , provide training to him & now company suffering . only they asked to stay only in case of workload only upto 7pm he denied(not even daily). timing was 10-6:30. They can file any case against company? There is no amount mentioned in offer letter but three months company paid by bank.

I think any legal person can give better suggestion for you.

Hi,
Your question is not clear.
Without appointment letter how that employee joined and worked for 3 months ?
What was the salary/Stipend fixed?
Has that employee signed any training agreement.
Offer letter is preliminary to appointment order. If Appointment order, that particular company can initiate disciplinary action for not reporting to duty without any information and can end in termination.
I think that employee is just threatening and try to gain some advantage. HR has to be strong and inform that disciplinary action will be initiated against him.

Thank you so much Sir for your guidance. Employee didn't sign the appointment letter and postponed it by excuses. He didn't sign any other agreement except offer letter. It's like he just learn as a fresher trainee & left after 3 months & asking for experience letter.
Thank you again V.M.Lakshminarayanan Sir

Stipend as per minimum wages they given as per shop & establishment 284 semi-skilled per day