This is a misconception that if a person is born on Tuesday, it will make him Manglik. Many people developed this notion because they thought as the day "Tuesday" is ruled by planet Mars, so the person getting born on Tuesday becomes Manglik. This is not true astrologically. There is no correlation between the day of birth and the Manglik characteristic of that person.
As per vedic astrology, each day of the week is associated to a graha. Tuesday is owned by Mars (Mangal). Many astrologers consider Mars to be naturally malefic planet as Mars being a fiery planet is considered to create turbulence in life. This is one of the strong reasons why it is considered inauspicious. The sense of in-auspiciousness lead people to start believing that birth on Tuesday makes the person Manglik. Actually this is not true.
What makes a Person Manglik: The positioning of planet Mars in the birth chart or horoscope of a person makes him Manglik or Non Manglik. If the planet Mars is positioned in any of the six houses 1st, 2nd, 4th,7th, 8th and 12th house in the birth chart, the person is supposed to be under the influence of Mangal Dosha as per Hindu astrology. But still there are other factors which decide whether the person is Manglik or Non Manglik. One can always consult a good astrologer to find out if the placement in the horoscope makes him or her Manglik or not,.
In nutshell, its the positioning of planet at the time of birth which decides whether the person is Manglik or not. Getting born on Tuesday has no direct correlation with the Manglik characteristics of a person.