Bsc is pure science.You can select it if u are very much passionate about a science subject. And if you can continue to masters and research, Bsc is nice option.
Btech is about engineering ... Makes use of these basic science in application in technology.and the branches are many that it's a bit confusing to choose from based on our likes and skill.
Job opportunities are similar in both. The more we learn and more exposure we attain during studies gains you better jobs.

Both are good for my openion I prefer engineering