Wheat ie sooji is also best avoided at six months. You can try making a porridge with rice or ragi, cook with water and when ready add either breast milk or formula

avoid cow milk if your kid is below 1 year though its easy to digest it may cause allergy. first test for any allergy by introducing in little quantities for few days then proceed

yes, obviously cows milk is best, as preservatives and other chemicals are not good for babies