See if you have complete Diploma in Mining Engineering then you are eligible for BTech through JELET provided you should satisfy the undermentioned eligibility criteria:

The candidate must have passed the diploma programme with minimum 45% aggregate marks (40% in case of SC, ST, OBC-A, OBC-B, PwD) or equivalent CGPA.

As a result if you score very good in JELET then only you can expect the JELET and the rank you should expect must be in top 100 as JU have less seats and higher competition. Also if you want you can change your stream in your BTech.

To know more about JELET visit the link below:

https://www.careers360.com/exams/jelet

TO know more about JU visit the link below:

https://www.careers360.com/university/jadavpur-university-kolkata

I hope this answer helps. All the very best for your future endeavors!