Mother last name in 156 form

[Akumar]

Hi,

My mother last name is missing in her passport, we just recently noticed and we don't have time to correct the same in passport, my mother is going for visa on Dec 2, what should I mention in D-156 form last name column, can I just leave it as blank

Please advice
kumar

[Murali]

do as per the pssport.
Later in future get that rectified in passport.