How to send sms from a GSM Mobile phone using VB Code. Kindly tell me what are the prerequisite for this. Kinldy tell me the steps. Kindly tell me about gateway.

Read https://www.daniweb.com/programming/threads/435023/read-this-before-posting-a-question again.

It appears you may have not tried anything yet. That is, this is not that you can't go ahead and ask how much someone will create this for you as in hiring for the job.

But it's a shame you are asking for VB6 as that is now long gone and rare. Why not go with a system we can get today? (you might have found a copy but it's a shame to start your new app on such an old system.) Besides where will this help you develop a system you can get help on today?