The proto-states of the Gangetic region were known as janapadas and comprised chiefdoms, republics and small kingdoms. Sixteen mahajanapadas find mention in the early texts.  

• There were also ganasanghas or oligarchies, which were centred on clans. The Vrijjis were one of the best known of the gana-sanghas, and Vaishali was their capital in the Mithila region.  
• These kingdoms did not come under the single decision-making authority of a king but decisions were taken on a collective basis by the heads of the different clans together.  
• There were also smaller kingdoms such as Kosala and Kasi. It is interesting to note that the names of the clans, such as Ikshvaku and Vrishni, as well as these early kingdoms, are all mentioned in the two epics, Ramayana and Mahabharata. 

Source: Tamil Nadu state board