birth certificate

Mga mommies n may indian husband or boyfriend...sa birth certificate nila ano ung middle name usually na gamit nila?un b ung name ng father nila?confused lang ako...for example sa Birth certificate nila ay RAM SINGH pero sa passport nila ay RAM PYAA SINGH..which is RAM ung name nila,PYAA is fathers name and then SINGH is last name.. SO alin jan ung middle name nila na same sa atin na may middle name..