Praman (प्रमाण) means a valid means of knowledge or evidence. It refers to how we know something to be true, and in Jainism the main pramanas are:

• Pratyaksha: direct perception
• Anumana: inference
• Aptavakya (scriptural testimony): the words of reliable scriptures

Yojaन (योगjan) or yojan (योजन) generally means a method, plan, arrangement, or a unit of distance used in ancient Indian texts. In Jain cosmology, yojana is primarily a measure of distance (a unit used to describe scales of the cosmos).

If you came across the compound “Praman yojan” in a specific text, it is not a standard, widely cited Jain term by itself. It could be a context-specific phrase (for example, “the measure of knowledge” in a metaphorical sense) rather than a fixed technical term across Jain literature. If you can share the exact verse or text where you saw it, I can give a precise, text-based explanation.

You can read more about Jain means of knowledge (praman) and related concepts on a Jain-focused page here