i have already learn how to use gaussian software from your suggested source. but my problem is that we have no gaussian software so i need help of someone institute which allows me to use gaussian software.
Gaussian is a program package with an individual license. Even institutional license has involved selected academics, which have purchased license for academic purposes.
In this context if you have not personal license or are not involved into a academic group having permission, than you should inspire a collaborative contacts with academics/researchers with topic in the field of the computational chemistry performing a common research on your idea/object if it find, of course, a reaction of interest.
Otherwise you could use the services of a given computational centres/clusters, however, they are no free of charge.
There are available large set of computational centres/clusters to many Universities/Chemistry Departments worldwide, which could provide you both possibilities for collaborative networks and/or computational services.
You need to get an account at a supercomputing center that offers Gaussian. The academic license is limited to users on campus. To offer Gaussian to the public, a commercial (or supercomputer center) license is required, at about five time the cost of an academic license.