All in three's group

Tripitak: a collection of the precepts of the Buddha; 1) Vinaya, 2) Abhidhamma & 3) Sutta Pitakas

Tridosh: the three humours of the body; 1) Phlegm, 2) Bile & 3) Wind
Triyan; the three vehicles of Buddhism; 1) Mahayana, 2) Hinayana & 3) Vajrayana
Triyug: the three Yugas; 1) Satya, 2) Treta & 3) Dwapar
Triratna: the three meals; 1) Gold, 2) Copper  & 3) Silver
Trilok: the three worlds; 1) Heaven, 2)Earth & 3) Hell
Triwarna: the three main colors; 1) Black, 2) Red & Yellow
Trikal: the three times; 1) Past,  2) Present & 3) Future                              Or 1) Morning, 2) Noon & 3) Evening
Trishakti: the three godly powers; 1) Desire, 2) Knowledge & 3) Performance

Triwarga: three human pursuits;  1) Love, 2) Duty &  3) Wealth

Tridewa: the Hindu trinity; 1) Gods Brahma, 2) Vishnu & 3) Shiva
Trifala: the three myroblans/ a mixture of three myrobalans; 1) Terminalia chebula, 2) Emblica Officinalis 3) Cherryplum

Tripurus: persons of three generations: 1) Father, 2) Grandfather & 3) Great grandfather

Trimadhu: a mixture of three sweets; 1) Ghee or butter, 2) Sugar & 3) Honey
Trikut:  1) Dry Ginger, 2) Black Pepper & 3) Peepala

Trigun: three qualities; 1) Sattwa or Soul, 2) Quality of passion & 3) Spirit tama

Three kinds of pain; 1) Spiritual, 2) First Vedic & 3) Material
Tridosh: the three faults; 1) Speech or promise, 2) Bile & 3) Cough
Trilinga: three genders; 1) Male, 2) Female & 3) Neuter
Three ways of feelings; 1) Literature, 2) Music & 3) Arts
Three truths 1) Image, 2) Practical & 3) Other menses