Retirement benefits and Pension benefits

Hi, My dad was an VAO Officer. And was placed under suspension by the RDO on the year 2000 and criminal case against him is registered in judiciary department. And RDO frames changes under 17 (b) of TamilNadu Civil services (Discipline and Appeal) act rules. But RDO failed to deliver the charge memo to my dad till date and no committee is formed to further enquire with my dad for representation on the charges. And his retirement date was on 2013. And no orders for not permitting him to retire was also served to him. And he was convinced in district court on 2015. And appeal was made on the high court on the 2015 as well. All of a sudden my dad died on 2017 October. And post to my dad died, it was also brought to my notice that 17 (c) of Tamil Nadu Civil services( Discipline and Appeal) act rules charge memo was prepared on 2017 July but again failed to deliver to my dad. Please suggest me, how to abate the charges of 17 (b) and 17(c) rules against my dad to get the retirement and Pension benefits and pending salary.