That first picture looks like normal wear and tear that you see on any plant this time of year. Life in the wild is hard, and any number of things may be abusing those leaves.
Is the tree in a pot? If so, some of what appears to be happening is salt damage, which is usually more acute in a potted plant than one grown directly in the ground. Most municipal water has a degree of salt in it due to the chlorine they use as well as naturally occurring salts in many water sources. If you are using chemical fertilizers, that's a big salt source. Salt builds up in the soil, particularly with potted plants. When you see burnt tips of leaves, that's a good indicator of salt damage.
I would flush the pot with a 2-minute heavy watering, so that water runs right out the bottom of the pot for a while. That'll wash a lot of the salt through the soil. Mangos are trees so they really don't want to be contained in a pot. Can you get it in the ground and let the poor tap root run free and go wild? If not, perhaps consider re-potting it in something much larger, and give it a big dose of well-made
compost. That would solve most concerns about nutrient deficiency.
Best of luck.
"The rule of no realm is mine. But all worthy things that are in peril as the world now stands, these are my care. And for my part, I shall not wholly fail in my task if anything that passes through this night can still grow fairer or bear fruit and flower again in days to come. For I too am a steward. Did you not know?" Gandolf