Is it possible to complete B.Tech, in 2022 after joining earlier in 2008?

In this type of courses generally the university or institution which conduct them give some time to the student to complete the course if it is not possible to do so by him within the stipulated four years time. Most of the colleges will give an extension of two years by which time the student has to complete the arrears and qualify in them.
In certain conditions if there is some genuine problem faced by the student like death of the father and taking care of the family or some such disaster then the university authorities can take a view on that and grant more extension on humanitarian grounds but that is done on a case to case basis and the student has to give enough evidence and justification for that.
The gap shown in this query is quite big and I am afraid that your friend has to do the whole thing again.

In your case, you have to approach the university officials for the better clarification of the enormous gap which has happened in your case. Normally an extension of two year is allowed to clear the backlog and hence in way the duration should exceed beyond 6 years. There is provision of issuance of NFT( Not fit for technical education) in the event of extension of the duration beyond the limit.
However, there is no hard and fast rule that the same regulations will hold good even your case. You may write an application to the university officials stating the facts compelled you for the discontinuation of the course. If the reasons indicated by you seem to be justified in the eyes of university officials, your case might be entertained. This could be your health angle and in that case, you need disclose the medical certificate of a competent doctor indicating the disorder with which suffered causing substantial dislocation in your career. Even the cases of calamities of your relatives will also be entertained.
The university officials would examine the merits in your case and accordingly a decision would be taken up by them. Meet personally with the university officials to expedite your case.

The chances are remote.
Your friend joined in 2008 in JNTU Kakinada and he is supposed to complete his course by 2012. As per the university grants commission's regulations, any university which is recognised by UGC should allow only 2 years time for completing the backlogs after completing 4 years of study. Under exceptional conditions, the University may allow one additional year for the candidate to complete the course. So your friend should have completed the back longs by 2015. But it has not happened. Already it is 2022 that means almost 7 years passed on after the permissible time. So I feel the university may not consider your friend to complete the backlogs now. He has to do again all the four years by joining the college.,
However, the candidate can go and meet the Registrar of the university and explain to him the reason for his non-completion and can ask for a chance. But the chances are very very less.