I am an Indian national. What is the maximum time of tourist visa that i can get?

Usually, you can get a L type with the validity of three months and 30 days duration of stay. If you get a single-entry one, you can try to extend it to acquire another 30 days from local entry and exit management bureau. Please remember that the extension should be done at least 7 days before your current one is expired.

To be honest, there is no time interval that you need to wait for applying for your second one.