Hi Ronak,
Well as stated from our previous reply the exact functionality that you need is supported by the TreeGrid and when applying this functionality to non TreeGrid it will be normal to have some compromises.
IF you want to get the checked rows/data/ just use the getSelection method of the SmartGrid like so:

  const result = this.grid.getSelection();

Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team