Yes, just take one of the exams at Pro level or above. so passing 1 exam from CCNP Security track will renew CCNP RS.
then, continue with Security exams and take CCNA Security within 3 years of passing 1st CCNP Security to get official CCNP Security.
Certs and Exams are valid for 3 years. To renew your Cert, just pass 1 of exams on the same level or higher level. Some small restriction apply (i.e. sales exams don't count). Exam does not have to be within same track. Passing 1 exam will renew current Certs for another 3 years.