Now the 4 siblings and my mother are applying for the khata to be made in 5 names. Is this correct? How does the Hindu succession act work here. All of my fathers siblings have children and grand children. When the property is sold, how will this be distributed?
If all the siblings of your father are alive then the khatha(joint) can be applied for on those four names along with the names of your mother, yours, your own siblings because all of you are entitled to a share out of your father's share in that property.
The wards of living siblings are not entitled to any share out of the shares of their living parent during their lifetime.
If the property is jointly sold then the sale consideration amount shall be divided into five shares and you and your family members shall be entitled to one such share.
She has obtained NOC from my sister, but mentioned I was abroad and left me out of this. I came to know about this through other sources. What should I do in such a case?
If your mother is turning hostile to you then you may immediately issue a legal notice to all of them, i.e., your father's siblings and your other and your own siblings seeking to partition the property into equal shares and allot you one such share in the property as per your entitlement in the jointly held property.