I am b.tech student I want to apply for gov jobs I dont known how to apply could help me.

Hello,
As a B. Tech student you can secure government jobs in India through various competitive examinations like GATE, IES, SSC, etc.. Identify your interest and suitable areas, based on that you can decide which will suit you.
I have attached the link listing Top government jobs after you can try and do after B. Tech. Kindly click the below link and know the details.
https://www.careers360.com/courses/articles/top-government-jobs-after-btech-degree-in-india
For application process you can check the official websites of respective exams and create profile. Then you can apply and start your preparation.
I hope this helps you.