NEM Transaction fees

What is transaction fees in nem transactions & in mosaic transaction ?

In both you have to have some xems, no matter what mosaic are you sending. Also, there are mosaics that can have additional fees called levy. For example if you want to send dimcoins, you have to pay tx fee in xem, and additionally 0,1% amount of dimcoins you are sending.

Thanks but what are the ranges for transaction fees ? From nem explorer list I found various values like 0.2 ,03 etc

From 0.05 to 1.25 for transaction + additional cost for message if included.
More information here: https://nemproject.github.io/#transaction-fees