Suggest me any other good b.tech entrance exam whose application form can still be filled other than UPES Dehradun?

Hello Aspirant, there are plethora of options you can go for right now. But whether you find them good or not is very subjective.

1. IPU CET 2019
Last date to apply for B.Tech Biotechnology is April 29, 2019.
For other B.Tech programmes you will have to submit your application by first week of May, 2019. But the admission to these B.Tech courses will be on the basis of JEE Main Paper 1 except for biotechnology.
Exam date - May 26, 2019

2. TS EAMCET 2019
It is the Telangana State Engineering, Agriculture & Medical Common Entrance Test conducted by Jawaharlal Nehru Technological University, Hyderabad.
Last date to fill this online application form with a late fee of ₹10000 is April 28, 2019.
Exam date - 3rd, 4th and 6th April, 2019

3. BVP CET 2019
The examination is Bharti Vidyapeeth deemed University Common Entrance Test conducted by Bharti Vidyapeeth deemed University, Pune.
Last date to fill it's application is May 10, 2019.
Exam date - May 26, 2019

4. HPCET 2019
This entrance exam is conducted by Himachal Pradesh Technical University.
Last date to apply for the same is April 28, 2019.
Exam date - May 12, 2019

5. GEEE 2019
This test is conducted by Galgotias University.
Last date to apply - 31st May, 2019
Exam date - 15th June, 2019

6. AISECT Joint Entrance Exam
This annual entrance test is conducted by AISECT Group of Universities.
The online application form is open till 2nd May 2019 tentatively. And the exam date is 6th May 2019 tentatively.

7. NPAT UG 2019
This exam is conducted by Narsee Monjee Institute of Management Studies (NMIMS), for the admission to its Mumbai and Shirpur campuses.
Last date to apply for this examination is April 29, 2019.
Exam date - May 11 and 12, 2019

8. IMU CET 2019
Indian Maritime University conducts this examination. Last date to apply for the same is May 8, 2019.
Exam date -  June 1, 2019

9. DUET
Delhi University conducts this entrance examination, and the application process will start from 7th May, 2019 tentatively.

10. Banasthali Vidyapith Aptitude Test
This exam is conducted by Banasthali University, and the last date to apply is 30th April, 2019.
Tentative exam date for B.Tech - 1st June, 2019

I would recommend you to check the eligibility criteria of the examination you are willing to apply for. This can be done by visiting their official website and downloading the information brochure.

All the best!
I hope this helps.