I am planning to restructure navigation of my site, that include moving some links in other category. So i was thinking to use 301 redirects in .htaccess to perform these changes. So i was little bit confused that is there any restriction of number of 301 redirects using .htaccess?
Too many redirects, regardless of how they're implemented, can cause performance problems. The impact would depend on how many redirects you have, the CPU/memory/disk performance of your server, and the number of HTTP requests you receive per unit time. The only way to tell is to test.
A quick search over the forums here [google.com] will turn up plenty of reading on the topic, compose. That's where I located the quotation ;)