Cardiff University is in Cardiff, Wales, not London. You can find some information for PG courses in this pdf http://www.cardiff.ac.uk/__data/assets/pdf_file/0006/999429/Cardiff-Postgraduate-Open-Day-Nov-2017.pdf
Your questions and the answers would be
We have to write IELTS exam or is 12th English subject marks enough?
The Pg Diploma in Diabetes is a postgraduate course, the introductory lectures are being offered in England,Dubai and India based on the date availability. You need to meet the basic level of English competency.If the MBBS and examinations have been in English, you need a letter to support from the college or University for your exemption from IELTS.
Is it better to do Diabetology course from UK or from Chennai?
Very good question. Many doctors do degrees from overseas only to find that the state medical council and MCI do not recognize it. If your PG degree is not on your state license, then it would not be accepted by medical colleges or sometimes when there is a medico-legal case. For instance, FRCS for surgeons was not recognized for surgeons for many years until a few years back when MCI changed it's stance and accepted it. So, Please check with your state medical council before applying. Common knowledge and practice are to have an Indian qualification that's eligible for entry into the State license and then go for other foreign degrees.
What is the selection procedure?
Your basic MMBS degree access to treat patients with diabetes at the primary care level should be sufficient.
Is there any entrance exam for that?
As far as the website describes, there are no entrance exams. Please contact
firstname.lastname@example.org for this and the previous questions
Directly after completing MBBS can we join or any working experience is needed?
Based on the aim of the course, it implies that you need access to treat diabetic patients and do the coursework. So it would be preferable to be working.
What will be the fees structure for 2 years?
The fee structure is variable for EU, Non EU and international students. It comes to around 4250 pounds/year But please check with email@example.com
Will we get any scholarship?
There are some scholarships listed you need to contact them directly. http://www.cardiff.ac.uk/study/international/funding-and-fees/international-scholarships
Is there any hospital in India in collaboration with Cardiff UK offering this course?
Since you are in Chennai, please visit MV Diabetes center as they would be having international ties.
What is the validity of the certificate?
It is not clear.
I would suggest you contact the college directly for further clarifications to avoid confusions later on.
Phone: +44 (0)2920 874432
Fax: +44 (0)2920 874622
Phone: +44 (0)29 2087 9999