The intellect[buddhi] and the mind [manas] are not physical organs. The mind [‘manas’] is nothing but a collection of thoughts. Thoughts owing to imagination and impressions of observed objects constitute the mind. Emotions like fear, anger, lust, etc. are dimensions of the mind. The intellect [‘buddhi’] is that sheath which is responsible for analysis and rational discrimination based on previously known facts.
For more information on this, visit http://beta.namadwaar.org/answers-questions/what-is-the-difference-between-manas-and-budhi/