List only parent category

Hi,

First of all thanks for providing me such a great plugin. I am using this plugin for subcategory list and it works. For this we using http://sehpaathi.in/?json=get_category_index&parent=297. Assuming if i list all subcategory for parent category which id is 297.

But my question is that if require list only those category which is parent means only main category not list sub categories how can we do that.

Please tell me.

Thanks

https://ww.wp.xz.cn/plugins/json-api/