1. Chandigarh University is approved by AICTE and UGC

2. This means BTech degree from CU is valid in most states

3. Bihar Engineering Services needs valid BTech from approved college

4. CU BTech is accepted for Bihar UGEAC and govt jobs

5. You can apply if all your documents are correct

6. So yes your BTech from CU is accepted in Bihar

https://engineering.careers360.com/articles/bihar-ugeac-counselling