can i run a pathology lab by my own after doing diploma in clinical pathology
No You can't run a pathology lab by your own. As per the order of supreme court judgement in 2018 it was clearly mentioned that one is eligible to open his /her own laboratory after MD path , DPB, DCB.
So you have to hire a destined signing authority and a plan to license your Pathology Lab as per the government rules.
To get the NABL guidelines for opening a lab you may follow the link provided below:
http://nabl-india.org/nabl/file_download.php?filename=201210170522-NABL-112-doc.pdf
I hope my answer helps. All the very best for your future endeavors!