Browning edges and curling leaves

I found leaves of my Tulsi and even rose plants is developing total browning and scrothing starting from edges and well and curling down.

I am worried becuase I am not sure if it is due to heat 40+ degree or some kind of fungus or pests OR it is some nutrition issue like overdoes of some nutrition deficiency of macro or micronutrients.

Any expert advice help be helpful

I have attached some pictures.