1. In Hinduism, the second ‘limb’ of ‘eight-limbed’ (aṣṭaṇga) or rāja yoga concerning self-discipline to help purify the mind of impediments (kleśa).
2. In Buddhism, the constraints which control eventualities into their outcomes: (i) bījaniyama, biological or hereditary constraints; (ii) mano- or citta-niyama, unwilled operations of the mental order; (iii) karma-niyama, the consequences of volitional dispositions; (iv) uti-niyama, constraints in the physical environment; (v) dharma-niyama, constraints derived from the transcendental order. From these, it will be seen that events cannot be construed as the simple working out of karma, as though all eventualities must have a preceding karmic cause.
"Niyama." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (September 22, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/niyama
"Niyama." The Concise Oxford Dictionary of World Religions. . Retrieved September 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/niyama