Hi, so sorry to say your Bsc agricultural score is of no good in getting you a BTech college based on that score.

However you can apply for private colleges, it is always an option.

The other option is that you can take a year off and prepare for entrance exam for BTech college of your choice.

Applying for BTech private colleges is fine, just look at their curriculum and talk to their recent passouts for better understanding of the college environment.

If you have time then you can take a year for preparation and again apply for BTech government colleges.

Remember CS placements totally depends upon your skills not on your degree.

So I'd suggest you to work on your skills and be the best in your field. Then only you can expect your dream package/company.

Hope this is helpful.