If you have the right skills then you will not face any problem. See during the placement, the companies try to find candidates who have the required skills. So if you learn the coding languages such as C, C++, JAVA, SQL in your UG course well. The you have nothing to worry about and you will get a placement easily. The score of 10th and 12th willn't influence in any ways.

For placement tips consider the link below:

https://engineering.careers360.com/articles/10-tips-for-placement-interviews

I hope this helps. Wish you a great eve!