Work opportunities for senior management profile

what kind of work opportunities are available for people in age bracket 45-50 years and senior management work experience.

Not my intention to sound negative, but as has been written here, it would be far preferable if a man with your qualifications were to sound out the nepali job market in your own country, prior to arrival in Nepal. Submit your Curriculum Vitae to as many organizations as you can find in the field of endeavor which is of interest to you. By going through the internet, you should be able to identify a good number of would-be employers. Contact them to start, first in writing and maybe with phone follow-up. Depending on which activity you are in, give priority to international organizations, NGO's as applicable, and generally speaking, any larger organization which you have determined is already established here in Nepal. This way, you are likely to be able to obtain higher remuneration, perks, insurance, and other benefits.
By going to Nepal, empty handed - having applied nowhere beforehand - and on what I would call a wild spec, is in my humble opinion, a mistake. Put all the chances on your side. At the risk of repeating myself, better line up and secure the job first. Avoid possible disappointment that way.

In reply to question you had, press guy Rajan Pokhrel just anounced that they have more than 100 vacant positions for air traffic controllers at our main TIA (airport)

Upper level positions are paid about $200 per month, although with experience and if they are desperate you could get as much as $300. You will need to invest $20,000 to get the resident VISA. Also, bring $2000 for a motorcycle or you will be riding the bus. At $5.00 per trip, your salary won't be able to pay the taxi fare to and from work. Western apartments start around $500 per month, so make sure you have an income of $1000+ coming in from outside the country so you can afford to work here.  It will take 1 - 6 years to get the work VISA, so be sure to have plenty of money to live on in the meantime. Also, while waiting, you are only allowed to stay in Nepal 5 months per year. So, pack light as you may be spending lots of time flying to other countries to hang out (Thailand and Malaysia are nice places to hang out.)

Alternately, get a residence VISA from an embassy in your home country. Then, you can wait the years in your home country. If you are willing to wait the few years for the VISA, have a steady income of $1000+ coming in and at least $20,000 in the bank, you should have no trouble getting a nice $200 per month senior management job in Nepal.

It is the land of opportunity for rich people who want to give money to Nepal.