Parshvanath Bhagwan had chief disciples called Ganadharas. According to Jain traditions:

• Śvetāmbara tradition: eight Ganadharas (chief disciples). The senior among them was Shubhdatta (Śubhadatta). ( en.wikipedia.org, jainknowledge.com)
• Digambara tradition: ten Ganadharas. The exact list differs from Śvetāmbara, but the lineage is described as having more Ganadharas in their accounts. ( digjainwiki.org)

In short, the number is eight Ganadharas in Śvetāmbara texts and ten Ganadharas in Digambara texts. Parshvanath established the fourfold order and taught through these Ganadharas. You can read more here .

Note: Different Jain traditions (Śvetāmbara vs. Digambara) sometimes give different details about the exact list and number of Ganadharas.