Brahmins are one of the caste (or group) in India.
They are Hindus but have their own unique culture and tradition.
Here are some tips for parents when you search a match for your son or daughter on line using matrimony sites.

• Verify that the site has good number of profiles
• Verify that the site has some kind of accreditation; one of the things you should look for is whether the site has been approved by trust guard, a service provided to validate the authenticity of websites.
  
• When you post the profile do not put any contact information like email, phone number, mobile number or address in the body.
  This will result in spammers sending you unsolicited emails and mails.
  
• Be careful when dealing with a prospective match.
  Nowadays there are many con men who try to take advantage of innocent victims.
  
• If possible do a background check.
  
• Before marriage do a medical test on both bride and the groom.
  
• If the bride or groom is employed in a well known company, then Google the name or check the profile in Linkedin.
  
• Do a telephone contact first and get the pulse.
  
• Make sure to visit the profile's work place as well as home.
  
• Do a general talk to the neighbors and get a feeling of the family.
  
• Do horoscope matching before you go deep if you believe in horoscopes and Hindu astrology.
  
• If the profile does not match, then politely turn them away.
  Do not be harsh or make fun of the other person.
  
• Find the food and other habits of the match.
  

For more information check this for brahmim matrimony