There is a lot of opportunities for interested & willingful candidates in government sector.but as u see good future in that ,there is also great requirement of lots of effort ,practice & patience. If u want to go in PSU like BHEL ,BSNL , HPCL etc. U hav to score best in GATE EXAM . If u want to go in defence then also they will see ur academic performance as well as gate score same in other govt departments.u can also give CDS ,IES & other upsc exams .
Decide any one or last two things ( other one in option not more than that) ,pick out complete detalis of it ,from registration notes mock test to complete process till ur call letter & prepare for it at least one year with 7–8 hour daily study practice & mock test which u can buy online of respective thing. And then give the exam at least 2 attempt.(very few student clear any exam of this type in one attempt)