As far as condonation of delay form 112 is concerned
my suggestion is as follows to satisfy icai
write a letter on plain paper stating reason for delay and requesting icai to condone delay adn give particulars of dd no. if any attached , and also provide one more letter from ur employer which will be in his letter head and it will be like your employer acceptance and what student said was true under his seal and signature, And provide if any proof was asked by icai in your case.
It will looks good if you prepare letter format in word format and take a print out and get it signed duly by you and your boss.
So you can go like this as per my knowledge
however there is no prescribed format on how to proceed in this case but concern is we need to satisfy the ICAI