hi,

see in general phd course duration is 3-4 years, but integrated phd means in that course you can learn about masters program as well as research program. the eligibility criteria for iisc phd course in biological sciences  is candidates with a Bachelor’s degree in Biology or Biotechnology or Chemistry or Physics or Mathematics or Pharmacy or  Veterinary Sciences or  Agriculture course pass holder under the  pattern of 10+2+3/4 system, also you need to qualify in jam 2020 if you are attempting to this year admission, now if you already enrolled for master, that also will no problem as there is no upper age limit, however your masters certificate may not be evaluated since minimum criteria is bachelors degree for integrated phd course.