Dear Aspirant ,
There is no fixed period of P.hd . It can take minimum of 3 year and maximum upto 5 or 6. The span of the course may vary depending on the institution . It may take long period of time because candidates have to do lots of research.

Hello Dear,

In many fields of study, you can choose between a Doctor of Philosophy (PhD) degree and a professional doctoral degree. As to your question as to how long it takes, it depends on how fast you have been able to produce a novel piece of work. If you have enough data within 3 years, you can finish your PhD in that time. Even in part time, they need to finish within 5–7 years. A PHD Chemistry, in any kind of reputed Indian university will take about six to complete, and according to the UGC, three years is the shortest duration to be awarded with a degree. The fees of a PHD Chemistry course varies from college to college, but it mostly sits between INR 80,000-3 LPA, as the average fees annually. For more information you can visit the link :

https://www.careers360.com/university/indian-institute-of-technology-dharwad/phd-chemistry-course

Good Luck