What government agency is responsible for Land Use Certificates?

Hello members,

After my grandparents died they left my mom a piece of land as an inheritance. The land is currently under my aunt's name. My mom has dual citizenship and aunt solely Vietnamese. They qualify for property transfer between siblings, exempting them from property transfer tax.

What government agency is responsible for issuing & transfer of Land Use Right Certificates & Titles?

Furthermore, my mom and aunt must prove their blood sibling relationship, how do we that? Are both their birth certificates enough? Are other documents sufficient?  What if either one has lost their birth certificate?

Thanks for any help :D

I don't know the answer to the first question. 

For the second question:  Pursuant to Article 11 of Circular No. 15/2015 / TT-BTP, a birth certificate (in your case, two) are proofs enough.

The same article indicates that In the absence of birth certificate/s, it is possible to use letters, movies, tapes, discs, and other objects to prove the relationship, with at least two relatives of the parents testifying.

Last but definitely not least, DNA is the best way to prove the relationship if the test is done at a medical establishment or an assessment agency established or recognized by the State.