Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Hyderabad to Lake Garda as you normally would.
For a flight from Hyderabad to Lake Garda, you will be flying from Rajiv Gandhi Intl. Hyderabad Rajiv Gandhi Intl (HYD) is just 17.5 km from the centre of the city.
Yes, there are multiple flights from Hyderabad to Lake Garda for under ₹ 83,900. The cheapest flight booked recently is on Emirates for just ₹ 83,825, but on average you can expect to pay ₹ 106,664.