I could not verify any Sikh Guru name mentioned in the accessible Terapanth Prabodh sources I checked. The available material describes Terapanth Prabodh as a devotional ballad about Acharya Bhikshu and his tradition, and the inspected verses focus on Bhikshu’s life, the formation of Terapanth, and the acharyas—not on Sikh Gurus. ( dokumen.pub)

So, based on the sources I could confirm, no Sikh Guru name and serial number could be reliably identified. If you want, I can help you search the exact verse or page from the Terapanth Prabodh text.