Are we liable to pay Income Tax which was levied on My father (now deceased)  

I have received a notice from income tax section 148 on 23rd December against my father who died on 2021 Decembe. We have communicated via our Chartered Accountant by uploading his Death Certificate. After 4 days tax authorities came and collected details like legal heir certificate and again send notice section 148 against my mother who is the legal..Weve again requested and received a personal hearing.. the hearing section is over and we are required to submit documents...What Should we do..Are we liable to pay tax.