Complex sentence: Sen had penned the elderly Muslim woman's character bearing Surekha Sikri (a non-Muslim actress) in mind, and incidentally, Sikri and Bhisham Sahni (a non-Muslim Hindi writer) were chosen to play the roles of the Muslim couple in the film.
Split into simpler sentences: Sen had penned the elderly Muslim woman's character bearing Surekha Sikri in mind. Eventually Sikri and Bhisham Sahni (a Hindi writer) were cast to play the roles of the Muslim couple in the film.