Similar domain name

I want to ask if having similar domain name is bad for seo and could i get sued? example is hitekno and heytekno. Both are .com…

Will it have problem?
Thank you, i hope someone could enlighten me

INC.com

INC.in

Both are different.

how about hitekno.,.com and heytekno…com… can they sue one another?

Both are different. So, I think so.