Isn't B. Tech available there?

No.

B.Tech is not there as it only offers below provided programs -

B.E.: Chemical
B.E.: Civil
B.E.: Computer Science
B.E.: Electrical and Electronics
B.E.: Electronics & Instrumentation
B.E.: Mechanical

B.E.: Manufacturing

To check the complete list, you can go through the below link -

http://bitsadmission.com/fdmain.aspx

Good Luck!!!