I was downloading 3 torrent in Tixati but around the halfway of each, download was stopped. For on torrent, the B/s IN hoovering from 100 up to 600, under status . However, there is no download. Would anyone, please tell me what is the problem and what to do, thanks.

As per your own description, this is not a bittorrent client (Tixati, or any other you'd use) issue.

If your torrents stop downloading mid way, it's because either they have no seeders with 100% of the files, or because they stopped seeding, or because your system stopped downloading them, or because something on the outside (such as your ISP, or the tracker from which you were downloading) stopped your download or your Internet connection. You'll just have to find out which of these it is - in case of doubt I would try asking on the site/tracker from which you're downloading, or as a last resort contacting your ISP customer support.