How to safely transfer joint property

My sister and I own 2 joint properties(self paid by both). Both of us are ladies. My sister died intestate few months back . Now her legal heirs are her husband and 23 year old son . My sister s husband and son ( my nephew) want me to keep both the properties fully, giving up their right in the properties . I am a little confused as to how it can be done as I am not a legal heir of my sister's share , but just a co owner . Also I was reading up that nephew to aunt gift doesn't fall under the definition of a relative under income tax 56(2)and becomes taxable in my hands . I know brother in law can gift to sister in law .What would be the way to do this without any income tax complications? Will this be my nephew gifting me or he is only relinquishing it and there won't be any income tax complications?what is the way to do -Noc, relinquishment or gift deed? Will there be any capital gain tax, income tax (if nephew gives to aunt)? Will I have to go through my brother in law to do this ? What is the simplest and safest way to do this. Thanks dear