I want to redirect one page to other in SEO. From where I can do it?

In your htaccess file

... or you can 301 with php before the headers are sent, often tidier for cleaning up stray garbage e.g. /oldpage.php?fart=3&cheese=1 or for transferring from a string based to a pretty url structure e.g. /products.php?cat=shoes&col=red to /products/shoes/red.

.htaccess is good for redirection, if you're using wordpress website then you redirection plugin, easy tool

You can add redirection code in .htaccess file but every time do changes with it is not an recommended way to do redirection. So I want to suggest you to add redirection through plugin to your website. I found one free plugin for that some days ago named Trash Duplicate and 301 Redirect → goo.gl/6eQWpI