Hukumar ta sanar da wakili.

In Hausa, a full clause usually needs a subject marker before the verb. So even when the subject noun is already stated, you still say:

Hukumar + ta + sanar

This is normal Hausa structure, not unnecessary repetition. The ta agrees with the subject and also helps mark the completed/perfective verb form.

Ta is the 3rd person singular feminine subject marker in this pattern. But Hausa gender is grammatical, not the same as real-world sex.

Hukuma is a grammatically feminine noun, so it takes ta, even though an agency is not female. In English, you would still translate it as it, not she.

The basic noun is hukuma. The form hukumar is the feminine specific/linked form, often used where English would say the agency/authority or a known agency in context.

Many feminine Hausa nouns ending in -a show -r in this kind of form.

This is the perfective/completive form. It usually describes a completed action, so English often translates it as a simple past:

ta sanar = informed / has informed

The exact English tense depends on context, but informed is the most natural basic translation here.

Yes. That is the safest way to learn it.

The verb is sanar, but learners very often meet it as sanar da, meaning something like inform, notify, announce, or make known, depending on context. Memorizing the whole pattern will help you use it more naturally.

Here da is not best understood as simple with or and.

It is the preposition used in the construction sanar da. Hausa da has several different uses, and this is one of them. In this sentence, the best approach is to treat sanar da as the normal verb pattern.

Wakili is the bare noun form, often understood as a representative/an agent.

Wakilin is a more specific/linked form, often corresponding to the representative or to a noun linked with something after it, as in:

wakilin kamfani = the company representative

So the bare form wakili is normal if the noun is not being specially marked as definite.

A useful way to break it down is:

Hukumar — subject noun
ta — subject marker
sanar da — verb phrase
wakili — object/complement

So the overall pattern is roughly:

subject noun + subject marker + verb phrase + object

Yes, if the subject is already clear from context.

Then ta on its own can mean she/it in this verb pattern. So:

ta sanar da wakili

can mean she informed a/the representative or it informed a/the representative, depending on the situation. Including Hukumar simply makes the subject explicit.