Regular pruning of diseased and damaged parts of the plants. Regular watering, proper ventilation & sunlight, organic manure & fertilizers application.

In general you can grrow in indirect bright light conditions like basil, rosemary, mint, Centella asiatica, Maghai paan / betel leaf.

Tulsi has been used for thousands of years in Ayurveda for its diverse healing properties apart from devotional purpose.

No, both are different plants, Tulsi which is commonly known as holy basil, where as mint tulsi is closely related to holy basil & doesn't have devotional property.

Stevia is a sugar substitute made from the leaves of the stevia plant. It's about 100 to 300 times sweeter than table sugar, but it has no carbohydrates, calories, or artificial ingredients.

Costus igneus, commonly known as insulin plant in India. Consumption of the leaves are believed to lower blood glucose levels, and diabetics.