claim case with out fir

hello all learned

my client met with an accident  before the 3  months  he has not lodged any complain because  the doer of  accdient assuered him that he will pay the  expense but now  he denied now my client would like to  lodge pettiton u/s 166 of mv act what he should do wiht out any kind of the  fir and panchnama the  claim is tenable or not  now he cam lodge the complain or not  pls  inform me  regards