Wisdom School of Management, Bangalore

Yes, you can. IGNOU and other open universities run bridge courses, so as to pursue Bachelor's degree. http://www.ignou.ac.in/ignou/aboutignou/school/soss/programmes/detail/145/2 click the link for more. There is no need at all for having class 11th and class 12th standard. Alternatively, pursue class 11th and class 12th standard via private mode or get admission in NIOS, then after pursue BA from distance or private mode.

Better you clear the backlog because neither college's nor the recruiters accept the students with backlog so better you study that subject and clear the exam.

If you have completed your Diploma, then you are eligible for admission in the second year in any branch. Many of the regular colleges offer distance B.Tech with a minimal fee. You need to find a good college for your degree.

It depends on your qualification, if you are class 10th pass, you can do Diploma in civil engineering, or if you are a class 12th pass out, you can do B.Tech civil engineering.

Sorry, WSM does not offer Diploma in mining.

Polytechnic Engineering Diploma by Wisdom School of Management, Bangalore is a distance/correspondence course.
Please refer to the link provided below for further details regarding this course.
https://www.shiksha.com/engineering/course/polytechnic-engineering-diploma-wisdom-school-of-management-bangalore-indiranagar-178791