The word gaṇa (Sanskrit: गण) in Sanskrit and Pali means "flock, troop, multitude, number, tribe, series or class". It can also be used to refer to a "body of attendants" and can refer to "a company, any assemblage or association of men formed for the attainment of the same aims". The word "gaṇa" can also refer to councils or assemblies convened to discuss matters of religion or other topics.
As Shiva's attendants
In Hinduism, the gana or bhutagana are attendants of Shiva who reside in chthonic and liminal locations such as cemeteries and charnel grounds. The bhutagana also attend Shiva on Mount Kailash. The story of creation of Virabhadra from the Shiva's lock and destruction of Daksha by Virabhadra and his ganas are popular stories from Shiv Mahapuran.
Pāṇini in his Sanskrit grammar used gana as:
संघोद्घौ गण प्रशंसयो Sanghoddhau gaṇa praśansayo
The Nāradasmṛti in Sanskrit mentions:
It shows that the ganatantra (republic) system of rule was prevalent in India since ancient times.
In Shanti Parva
A detailed analysis of the GANAS obtains in chapter 108 of Shanti Parva in which Yudhishthira asks Bhishma about the ganas: how do they increase, how do they defend themselves from the dividing-policy of enemies, what are their techniques in conquering enemies and in making friends, how do they hide their secret mantras. Bhishma's answers to these questions were recorded in the form of shlokas (verses) from 16 – 32 in Shanti Parva.,
व्रातं व्रातं गणम् गणम् Vrātam Vrātam gaṇam gaṇam
Ganatantra (republic) means a state run by assemblies.
The representative members of clans were known as ganas and their assembly as sanghas, there chief as ganadhipati or Ganesha and Ganapati.
In Buddhist literature
The Buddhist literature Mahabagga mentions that:
गण पूरकोवा भविस्सामीति Gaṇa pūrkovā bhavissāmīti
It indicates that an officer used to see the number of ganas and their koram in the Rajasabha (state assembly).
Buddhist books like ‘Pali-pitaka’, Majjhamnikaya, mahabagga, Avadana shataka mentioned ganas and sanghas. During Buddha's period India had 116 republics or ganasanghas. In Buddhist times, Gaṇas were assemblies of the Sanghas, early democratic republics known as Gaṇa-rājyas, literally "rule of the assembly", a term paralleling demo-kratia or soviet republic. The term was revived in Bhārata Gaṇarājya, the official name of the Republic of India.