Hi aspirant,

Yes you can make a career in engineering field if you have a diploma in Computer Science. To get admission in two colleges you would have to apply through lateral entry and you would get admission directly into the second year of college. It is important to know that top government colleges including IIT, NIT and IIIT does not offer lateral entry programs. The admission through lateral entry are majorly done through merit basis based upon the the performance at the end of diploma while some others conduct their own entrance examination. To know more about these colleges and their admission procedures you can visit the link given below

https://engineering.careers360.com/articles/b-tech-lateral-entry-in-government-college

Hope it helps!