The 12th house determines your next life. Because the principle of 7 lives depends on Karma. The 12th house determines the kindness of a person. If a person has a strong 12th house then, for sure they will enjoy the fruits of their good Karma and enjoy their life in the next birth.
Further, apart from astrology but still related to our religion especially, the attachment we have for something or someone determines what we will be in our next life and who we will encounter.
In the Bhagavad-Gita, Krishna says, “Whatever state of being one remembers when he quits his body, that state he will attain without fail.”
An example of this in our sacred Hindu scriptures is when king Bharata who suddenly fell into a crevice and was fatally injured. Lying there at the point of death, he visualised the deer suddenly appearing. Consequently, in his next life, King Bharata entered the body of a deer.
Though even in the body of a deer, he was able to continue his spiritual progress & he once again became detached from all material desires allowing him to become liberated.