Am I eligible to do a fellowship in UK or Australia if I have a diploma in orthopaedics from India?

Hello Ram,
For an orthopaedic fellowship in UK, the post qualification degrees they accept are DNB And MS. Therefore if you have either one of these (issued by the NBE)  then you are eligible for an orthopaedic fellowship in UK.
Check out their official page for further details :
http://posi.in/POSI-UK-Fellowship.html
In Australia, if any international medical graduates have obtained some specialist degrees overseas then they will have to check for the recognition of their qualification through the Australian medical council website  :  https://www.amc.org.au
After this,  international graduates with specialist degrees will have to undergo a vocational assessment at the Royal Australasian College of Surgeons  ( RACS).
If you pass these 2 levels of assessment and your degree is recognized by the AMC, you can apply for orthopaedic fellowship in Australia.
You can check their official website for any further details :  https://www.aoa.org.au/orthopaedic-training/international-medical-graduates
Hope this helps  :)