What type of vitamin can help brain and memory please?

Unscientific, but. There is very little rigorous evidence that vitamins can improve memory, but the best approach is to assure sufficient folate and B-12 and likely vitamin D levels should be in appropriate range. Some data on Vitamin E in Alzheimer's, but there one would select mixed tocopherols, and the Amsterdam study suggested adding 500 mg Vit C daily to the E.