Kindly suggest me that which type of font/text is suitable in AutoCAD drawings?

Try always to use the .SHX fonts instead of the true type fonts in your drawings. this will make your file smaller...

I always try and use Arial for Dimensions & Name of Room and Size.CityBlueprint & Calibri I like for Description. Arial Black & Swis721BlkOulBT for main Title

arial or romans