Śvetāmbara (Shvetambar) and Digambar sects arose after Mahavira, not during his time. The traditional view is that the division happened over several centuries and was largely complete by around the 5th century CE. In short:

• The split began in the centuries after Mahavira (roughly after 3rd century BCE to 1st CE in many accounts).
• The schism was largely complete by about the 5th century CE, with Śvetāmbara and Digambara becoming distinct traditions. You can read a concise timeline of this on Jain Knowledge’s discussions. ( jainknowledge.com)

Note: Different Jain sources may give slightly different dating for specific events (e.g., famine-era migrations and the Vallabhi council). The common Jain scholarly summary is that the two sects crystallized by the 5th century CE. You can read more about the broader background here: ( jainknowledge.com)

If you’d like, I can summarize the key points from the Jain Knowledge pages in simpler terms.