In kerala most people are known by the family name and not by the sir name . for example in my name Mullamangalam Thomas Jacob ,Mullamangalam is my family name and all my relatives on my fathers and fathers fathers side will or should have this name .
Thomas is my given name . There is a method by which this name is given in Kerala. the eldest son gets the fathers fathers name,the secon son gets the mothers fathers name and the third son gets the fathers name . the eldest daughter gets the fathers mothers name .the secon daughter gets the mothers mothers name and the third daughter gets the mothers name .
the advantage being that it is very easy to trace ones family and the disadvantage being that the names are often repeated .
At present many people do not follow this system for various reasons .
Jacob is in a sense my sir name as is followed by western cultures which is actually my fathers name .
because of the different systems being followed ,i am known as Thomas in india, Mr Jacob in the West and also as Mr. Mullamangalam in the Middle East as this name appears on my passport.