Defamation as slander

My question is related to a defamation notice received by Me and demanding slander charges for the damages incurred.. That's in a way of either by appearing in person and apologise to him.. His parents.. Locality.. Neighbourhood.. Family friends etc.. Or 500000 as compensation for the... I am married.. My daughter used to go to KARATEclasses along with my wife.. It started in Sep.. There wer interaction between my wife n master who had also shared that he is practicing law too..She started sharing things to him through calls and message and may be through regular meet ups in class. Over the period the issues at home started increasing and also I was told by my wife not to touch her,It continued and then I was told to sleep separately too.. It continued..One fine day I saw my wife passbook Wer there wer transactions of money sent by the so called skating master and lawyer.. In numbering as 1000.. 1000.. 15000...all 3 transaction wer oň different dates and wer also returned by wife too the next moment as she received and she still had 80 k in her account already... On asking to my wife she told it wer wrongful transfer by mistake n so on ețc..my daughter is 5 years and revealed that they had gone to temple with him also.. She claims he is a friend now.. But with the call records at odd timing and for hours throughout the day it's really not easy to conclude so.. Since Sep to November I have the call records wer my wife had called him and spoken for hours every day almost.. Plus I have screenshot of his messages at late night to my wife but just a word or so.. When I tried to enquire regarding him .. I had come to know that he is not a part of karate association.. He is not a lawyer yet and also misbehaved with some parent previously N was beaten up.. I took this thing softly and did not do much..my wife blackmailing me N widow mom in terms of false domestic violence case and getting us jailed and suicidal attempts with us being reason..I now enquired about the master and lawyer and when I went t his address it was known that he has shifted his home and so on..I wished to know the facts about him wer right or wrong..So when I discussed with a third party who is the secretary of the building and a family friend as to whether the person is really a lawyer and also that he is not part of the associations and so on and also the incident of misbehaving ..i just spoke with the intention of enquiring .. But that person has now sent me a defamation notice on such..Wer the facts about him being not a part of association was true..He was registered as lawyer on Aug 2021 only and also he has blamed me that I have stated that he had affairs in previous past with women and so on.. With the intention of monetary gains and etc.. Whereas the last statement was never ever proclaimed by me.. I have the entire recording of my conversation with the third party (3 members ) that has taken place at home only.. Is this a case of defamation...? Or how? Please help?