I found few dropped domains with very old backlinks in my niche. How is good if I make 301 redirect to my website's main page? Its get me something positive or not, what you think?
You don't want too many 301 redirects... If you have a number of them then consider mixing them up and use some to your money site and some to your other tier sites. Assuming the domains still have good/valid links and some authority, it will be passed on.
I realized that with a 301 redirect, all the links get listed to the other site on webmaster tools, so it might be good!