Is a witness's testimony of unconfirmed information regarding a person's presence in a dwelling considered perjury, and what is the way to atone for this sin?

Testimony is not permissible unless the witness has knowledge and certainty of it, as Allah Almighty says: "Except for those who testify to the truth, and they know" (Quran 43:86), and "And do not pursue that of which you have no knowledge" (Quran 17:36). This is further supported by the saying of Ibn Abbas, may Allah be pleased with them both: "The Messenger of Allah, peace and blessings be upon him, was asked about testimony. He said: 'Do you see the sun?' He replied: 'Yes.' He said: 'Testify to something similar to it, or leave it.'" Repentance from a sin involves abandoning it, regretting it, and resolving not to return to it, as well as returning injustices to their rightful owners. Repentance from false testimony includes mitigating its effects and restoring rights to their owners.