I will be applying Eea fp for me and my parents. I am non eu getting married to Eu. When my parents have residence card can they sponsor their son for Eea fp and residence card as he is dependent on them ?
If your spouse can claim a right of residence in the UK (e.g. if working in the UK), you also have a right of residence and are eligible for an EEA family permit. As parents-in-law of an EU citizen with a right of residence, your parents may also qualify, but only if they are dependent on you.
Being a family member or a dependant of your parents will not confer any special status. Your brother does not seem to qualify for any EEA permit.