we have done a process which has been already done around 50 years ago & is patented in US. We have just modified the process with no new invention done. we have just make the process just by introducing technology. Can it be patented in India?
While this site is mainly for patent applications in the US, I'm sure the presence of a US patent will prevent you from patenting the same thing elsewhere, even India. If the changes made are considerable enough to call it a new "thing", then perhaps - but you did say
We have just modified the process with no new invention done
You say "modified" but with no "invention". How do you judge if your modification is or is not inventive? Small modifications can have large, unexpected consequences. And large modifications can be not new or obvious.