All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
There is no blame on you to kiss the hands of your uncles and aunts to show them your respect and affection.
Abu Daawood and At-Tirmithi reported that the Prophet used to kiss his daughter Fatima and she kissed him when he visited her." In another narration: "He took her by hand and kissed her".
Thus, it becomes clear that kissing hands as mentioned above is permitted as long as there is no glorification of people.
In addition, both the kisser and the one whose hand is kissed should not have any form of desire while kissing. Otherwise, it becomes forbidden.
Allah knows best.