Hello,
If your question is ,
Can pursue diploma in mechanical engineering after  B.sc??
Diploma in mechanical engineering is a 3 year course, that any students pursue after class 10th if full fill eligibility criteria. This diploma course in mechanical engineering daal with design, Manufacturing, maintenance of mechanical equipment by using basic knowledge.
The  eligibility criteria for taking admission in diploma in mechanical engineering are :-

• Candidate Must pass class 10th
  
• Pass class 10th with minimum of 55% and 50% for reserved category
  
• subject like mathematics and Science are mandatory subject
  

So, after your BSc  you can surely pursue diploma in machanical engineering.
As you satisfying every eligibility criteria that require to get admission in diploma mechanical engineering.
All the best!!