<prompt> The most common causative agent of meningitis in the age group of 6 months -3 year amongst the following isStreptococcus agalactiaeH. influenzaeStaphylococcusN. gonorrhoeae  <response>: The most common meningitis occurs In case of 6 months to 3 yr old children is haemophilus influenza. Reference: GHAI Essential pediatrics, 8th edition 