is group 1 and 6 a ionic compound or molecular?

A Group 1 element and a Group 6 element form an ionic compound..

Excluding the radioactive elements, Group 1 elements (Li, Na, K, Rb, Cs) are metals, while Group 6 elements (O, S, Se, Te) are non-metals. A metal and a non-metal form an ionic compound.

Oversimplification.....

Many teachers tell students that a compound of a metal a nonmetal is "ionic." They go on to say that in "ionic" compounds electrons are completely transferred from the metal to the nonmetal. That turns out to not be the case in a large number of compounds in metals and nonmetals. That is an oversimplification. In fact, there are no 100% ionic bonds, and no complete transfer of electrons.

For example, the "poster-child" for ionic bonding is sodium chloride, NaCl. Yet the bonds in NaCl have about 70% ionic character (30% covalent character). The greater the difference in electronegativity between the elements, the greater the ionic character.
Bond .............% ionic character
Na - O ........... 79%
Na - S ........... 49%
Na - Se ......... 48%
Na - Te .......... 29%

The question should really ask about substances existing as discrete molecules compared to network solids. Na2O, Na2S, Na2Se, Na2Te all exist as networks, and none as discrete molecules, but to say the are all "ionic" isn't true.

Some compounds with high ionic character may exist as discrete molecules. When compounds which are normally network solids are in the gas phase they exist as discrete molecules, but the bonds are not "covalent."

*** Substances should be described as either existing as discrete molecules or as network solids. It is not accurate to describe them in terms of bonds.

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In order to calculate an approximate value for the percent ionic character, use this equation from Linus Pauling. It is based on the electronegativity difference, ΔEN:
............ ........... % ionic character = 100(1 - e^(-ΔEN²/4))