I fail in class 12 from cbse then I change my board and did 11 and 12th again from that board can i get admission in gud engineering college
If you have completed your 10+2 then you are eligible to take admission in engineering. You must have passed your 10th and 12th.
There are not a such condition that if you change your board then you could not take admission in engineering.
Good luck.
Now a days, you have to prepare for govt jobs like GATE after b.tech.
But if you are choose pvt comapany then they ask and you can tell them there are some money problem and preparation for JEE.