Please help in my dad's birth time rectification

[npavan]

Respected guruji's

My dad has 2-3 charts and they all show different lagnas. Please help in rectifying his birth time and fixing the correct lagna.
DOB: Oct 24 1951
POB: Nellore, India
TOB: 5:30 AM (As given by his parents)

Major events in his life
Marriage: 28 April 1977
First son: May 12 1978
Second son: August 13 1981.
My grandmother passed away in May 9th 1990
My grandfather passed away on Dec 4th 2000
My mother had a major spine surgery on Jul 30 2010

My mother's DOB Jan 24 1954 POB: Vizianagaram India TOB:8:15 AM

In 1990 he left a well paid job and entered into business and lost all the money and relations were strained with in-laws as business was done in partnership , again he worked for few years and loaned some money to brother in law and lost all that money. Had to give a lot of money to others where he had to give but could never recover from place where he had to get.

At present he is working and would like to work for few more years. He is presently starting Mars mahadasha but he is posted in a far away place and is on leave to help my mother in recovery after surgery. Is there any chance for his transfer to local place?

Thanks