How long it takes for I-130 to be approved?

If the petition is prepared right, the approval will take from 5 months to 1 year (depending on the Service Center where it will be processed). The processing time, with few exceptions, does not depend on your nationality. Approval of the immigrant petition, by itself, gives you no right to remain in the U.S., no employment authorization, and no right to apply for adjustment of status.You will have to wait until an immigrant visa will become available to you, which, in your case, will take about 11.5 years. If you cannot stay in the U.S. legally until that time, you have to leave and wait for the U.S. Consul in Cameroon to invite you for a visa interview. If you fall out of status and remain in the U.S. illegally, when your turn to receive an immigrant visa comes, it will be useless to you: simply speaking, if you have no status, you cannot adjust status because you have nothing to adjust. You might have a shorter road to U.S. residency if you find an employer willing to sponsor you for a non-immigrant worker's visa.

You will want to review the Department of State Visa Bulletin. It will be many, many years for a priority date to become current. Until that time, you will either need to leave the US or maintain valid non immigrant status, as either a student or under an H-1b or other employment based visa.

1. It takes about 10-12 years for an immigrant visa petition number to become available for a sibling of a US citizen. It does somewhat depend on the country of birth but this timeframe is for worldwide and Cameroon would come under this. 2. You cannot apply to change status even if the I-130 is approved UNLESS and UNTIL the visa number is available and the wait for that, as I stated above, is going to be about 10-12 years. You should seriously consider employment-based options since you apparently have a degree and can get a job in the US based on your education.

Petitions for brothers and sisters of US citizen take at least 8-10 years before a visa number becomes available. In order to apply for adjustment of status in the US when your visa number becomes available, you must still be in status at the time of filing. It will be difficult for you to maintain status for another 8-10 years, unless you successfully apply for an extension or a change your status to another nonimmigrant visa (H1-B, F-1, etc.).