Relevent Law and Procedure

I am a resident of Bangkok, Thailand. My Dad have 5 children, The eldest is a daughter from first marriage. Upon the death of his first wife he married again and from her he have 2 sons and 2 daughters. My mother passed away in may 2014. Both mother and father are Indian Citizen while me and my brother hold Thai Citizenship and OCI. All three of our sisters are married and settled in India in the state of Uttar Pradesh. There is a number of property some ancestral and some acquired. The ancestral property is in my dad's name but acquired property is in the name of mother w/o dad's name. Same is the case with bank accounts and lockers. My Mother died without a will or nominee. She is survived by her husband, my Dad and 5 kids as mentioned above. My questions: 1) What is the legal procedure to get the name changed on the property under her name? 2) The exact wording of the law that governs it. 3) Whose name should be on the property document legally? 4) If the sons want only their name to be on the property document then what are the steps and documents required? 5) Will it be considered a case of fraud if one of the sons has successfully transferred the name on the property document in the name of both the brothers, without consent of sisters, father and one of the brother. I will be very thankful to the people who can answer it, I will be grateful if the relevant quotation (exact wording of the law) is used with section numbers and law name as this will go a long way in filing a complaint. If possible you can also email me at [deleted]