There is no such word as radionic in English. Nigerians normally use this word to refer to someone repairing their home appliances. Instead of saying radionic, the apt word is technician.

Electronics means technology of electronic devices: the branch of technology concerned with the design, manufacture, and maintenance of electronic devices (takes a singular verb)

However, there is radionics: use of electronic diagnostic device: the use in alternative medicine of an electronic device that can detect vitamin and mineral deficiencies from a hair sample or can detect subtle energy changes in the body.

The two words are close in spelling but their meanings are quite different. A complement is something added to perfect a thing and make it complete, whereas a compliment is an expression of praise:

• A fine wine is the perfect complement to good cooking.
• The cook received many compliments from the guests that evening.
  
  Both words are also used as verbs, and both have adjectival forms: complementary and complimentary. Complimentary has the special meaning "given free"; and so a complimentary copy of a book is one given without charge, whereas a complementary copy is one that completes a set of books.