probably no more than 20, seperated by a comma. Don't forget google doesn't use the meta tag for ranking
u can used in meta tag: Title: 60 - 70 characters Des: 150- 160 characters Keywords: 250-260 Characters
You can use: Title Tag: 60-80 char Meta Desc Tag: 150-200 char Meta Keywords Tag: 8 - 10 words separated by comas (Meta Keywords tag is not of much importance for ranking, there is no specific limit but you should not spam / stuff it with keywords).
no no meta description tag:80-100 meta keyword tag:5-10 (per web page where you are targeting the keyword in the post )
Hello Rajeshwarikshah~!! Words depend on the particular define meta tags. First of all u decide which meta tag do u use.... For example:- Title: 60 - 70 characters Description: 120- 150 characters etc.. I hope I was able to explain this..........