The correct passive voice of the given sentence is The house will be cleaned by our maid every Saturday from today onwards.

The active voice of the sentence is Our maid will clean the house every Saturday from today onwards. This sentence is in the simple future tense, which is used to describe an action that will happen in the future. The passive voice of the sentence is formed by putting the subject of the active sentence after the verb "to be" and the past participle of the main verb. In this case, the subject of the active sentence is "our maid" and the main verb is "clean." The past participle of "clean" is "cleaned." So, the passive form of the sentence is The house will be cleaned by our maid every Saturday from today onwards.

The other options are incorrect because:

• The house shall be cleaned by our maid every Saturday from today onwards. is in the present subjunctive mood, which is used to express wishes or requests.
• The house will have been cleaned by our maid every Saturday from today onwards. is in the future perfect tense, while the original sentence is in the simple future tense.
• The house will be cleaning by our maid every Saturday from today onwards. is grammatically incorrect. The verb "will be cleaning" is in the present progressive tense, which is used to describe an ongoing action. The passive voice of the sentence should be in the simple future tense.