For the domestic tax program at NYU, does anyone know if it is easier to get into the advanced certificate program when compared to the part time llm program? I read that you can transfer to the part time llm after you complete the certificate. Thanks.

Same admissions standards. "the standards of admission are the same for all specializations and countries..."
http://www.law.nyu.edu/llmjsd/graduateadmissions/onlineinformationsession/onlineinformationsessionam/index.htm

I think you may have to reapply if you want to go from the certificate to the LL.M.