Considering that the specifications of Nezirus are not drinking wine, not becoming Tamei Meis and letting one's hair grow long, what is the Torah saying here?
Ramban #1: What the Torah is saying here is 'This (the above) is the law of the Nazir who takes the Nazarite vow
What are the implications of the phrase "Mil'vad asher Tasig Yado"?
Rashi and Ramban #1: It implies that if a Nazir undertakes to become a Nazir on a hundred Olos and a hundred Shelamim, the Neder is valid and that is what he is obligated to do, as the Pasuk goes on to explain.
Ramban #2: It implies that if the Nazir is wealthy, he should bring additional Korbanos.
And what are the ramifications of the words "Al Toras Nidro"?
Rashi and Ramban: Although the Nazir is permitted to add to the basic requirements of a Korban Nazir, he is not allowed to detract from them. Consequently, if he undertakes five Neziros on condition that he brings three sets of Korbanos, "Ka'asher Yidor kein Ya'aseh" does not apply to him, and he is obligated to bring five sets of Korbanos.