Can someone advice me?

I wasn't able to find anything about a maximum time limit. That being said I have copied relevant sections from the Ohio application here:

Foreign Educated Applicants

Contact The Commission on Graduates of Foreign Nursing Schools (CGFNS) at (215) 349-8767 and request the Credentials Evaluation

Service (CES) Professional Report. The report must be sent directly from CGFNS to the Board.

4. English Proficiency for Foreign Educated Applicants

Proof of English proficiency is required and may be met by satisfactorily completing the “Test of English as a Foreign Language” Effective 10/2013 2

(TOEFL iBT). All applicants must achieve a minimum passing score of 83 or higher. Test scores must be sent directly to the

Board from the testing agency. Contac Educational Testing Services (ETS) at (609) 771-7100. This requirement does not apply to a

foreign educated nurse graduate who graduated from a college, university, or professional education program located in Australia,

Ireland, New Zealand, the United Kingdom, South Africa, Trinidad and Tobago, Jamaica, Barbados, or Canada (except Quebec unless the

individual graduated from McGill University, Dawson College in Montreal, Vanier College in St. Laurent, John Abbot College in Sainte-Annede-Bellevue

or Heritage College in Gatineau).

I would HIGHLY recommend that you take a review course of some kind. Research data indicates that an internationally educated test taker who waits longer than a year after graduation to sit for the NCLEX has less than a 50% pass rate on the first attempt. Give yourself the best shot you can and take a refresher course.