Thank you govpatel. At one time earlier also I uploaded at the root and I was able to install. It was working fine. There after I changed theme and uploaded few plugin, then only it did not work. I have the permissions to create data base too in the control panel and I have tried that too. There after I deleted the database name and created with another name and then again downloaded, unzipped, re-configured config, uploaded and tried /wp-admin/install.php, it did not work.
There after I have deleted all and then uploaded entire again in the directory, but still it did not work. No message comes when the install command is executed.
Please help me.