There are 15 admission categories for getting a temporary or permanent visas, according the Immigration Law (L 25871) in Argentina, as appear in articles 10th, 20 to 23th. This categories are:

Art. 22 - Spouse, son, daughter and parents of Argentinean citizens.

Art. 23 - a) Migrant worker; b) Financier; c) Pensioner; d) Investor; e) Scientific and Specialized Personnel; f) Sportsmen and Artists; g) Religious Ministers; h) Patients low medical treatment; i) Academics; j) Students; k) Refugees;  l) Nationality (Citizens of Mercosur, Bolivia, Chile); m) Humanitarian Reason; n) Special.


Art. 10 -  For family reunification - For spouse´s residents or his/her parents, children smaller than 21 years and bigger children with different capacities (handicapped).
Obviously that each one will analyze the category that correspond him/her, and it should also be verified if it is reached by some Special Regularization Program or special Agreement, like there are with Bolivia and Peru. After this analysis, it will be evaluated how to prove before the Immigration Office, the capacity in the admissionm category elected, remembering that true evidences are demanded.

It is ESSENTIAL a Visa or Disposition like permanent or temporary resident (NOT TRANSITORY VISA), for having an authorization to work according to some of the categories mentioned up. The precariou residence, granted by the Immigration Office, enables to work too, but it is not the same to Entry Permits that do nott enable to work but to obtain a Visa in Argentinean consulates.
 
Also, it is authorized to work for brief time who gets visa or authorization for 15 fays as transitory status according to the normative or effective agreement, except in the case of Brazilian citizens that can work for a special Agreement while they are tourists.

Some recommendations that can help you:

1 -Original certificates. Get Original (or Certified Copies from an Official Register - Not Notarial copies) _Birth Certificates, Marriage Certificates, Criminal records or any other one, verifying the accuracy in all the data. Remember that for example, a name more or less, a single wrong letter in names or surnames that are not similar in all the documents avoids the administrative procedure.

2 - Enough legalizations are needed.  If your country had signed the Agreement of The Hague (Apostille), you should ask this APOSTILLE in the offices related to the Chancelleries of the country which originated the document. In all other case, the documentation should be legalized in Argentine Consulates of the jurisdiction where the same one was emitted. Keep in mind that: usually Foreign Documents will be NOT LEGALIZATED IN ARGENTINA in the consulate of the country who emitted this paper, except for very special cases as Bolivia and Peru. (please, See Agreements).

3 - Evident documentation.  To prove the requirements related to the diferents applications, it is asked a lot of requeriments, but as a general pointview the key is to understand that Immigration Office accepts as valid only EVIDENT documents, what means that common copies, letters or contracts with signatures non notarizated, the absence of enough prove to demonstrate existence and actual operation of a company, etc...  will be not accepted as appropriate documentation and to suppose the opposite will generate unnecessary delays.

Authorization for getting residences. For the cases the parents continues residing outside, it should be known that the Immigration Office will always demand the ausent father's or mother documenttation where he or she expresses authorization in favour of his/her son/daughter for going outside Argentina after they have the new residences. For legalizng this authorization see point 3.2 above.

Also it should be verified if the family reunification migratory requirements will be completed in order to the Immigratiojn Law (art. 10) and another normatives.