hi i've just installed smf at my site studentlife.co.in/ forum and in registration captcha images are not properly visible and on some devices it shows same captcha code
I've had this problem myself. Some of those captcha/anti-spam mods actually can interfere with registration. If you have any additional anti-spam mods installed try removing them one by one and testing the registration.
If you just installed smf, and your already having problems, that is a bad sign. Since this is a new forum, I really suggest you use something else. Get rid of smf and go with mybb. It has been years since smf has had a serious update, its a popular target of spammers, the themes are difficult to work with,,,,,,. I gave up on smf about 3 years ago. I setup a computer gaming forum with smf and the spammers had a field day.
SMF gets updated every 3-4 months. With new security releases. I don't agree with editing the themes is hard because it's not. You may need to contact your has as the HD may be damaged for the images to display on registration page.
That is the only thing that is getting updated - security patches. SMF 2 has been in beta phase for years. Where mybb is releasing new features with its updates, smf is releasing nothing but security patches. Maybe if php is a second language, maybe then editing the themes is not complicated. Even some of the SMF developers have said editing the theme is overally complicated. Just try adding a link to the navbar, there is all kinds of code you have to dig through.