Hi Aspirant,
There are many things you can do after your b.tech.
You can either go for a job through your campus placements or study further.
After diploma,if you apply for BCA and then later do MCA.
Also,you can do several other courses such as CAD,designing etc which will enhance your profile and get you paid higher.
If you interested in computers,then you can go for several other courses like C++,C,Java,.NET or any other valid course.
So,in a nutshell,the options are plenty where you can go.
Hope this helps.