I have an opamp. I use it as a buffer and its output voltage 0.5V. If i connect output of the opamp to the +5V supply with a 6.2k resistance, can opamp sink current.(opamp supply voltage +5V - 0V)
For the specified output voltage and resistor the current will be 0.7mA as noted in the previous post.
You didn't specify your opamp and you didn't post any schematic but the current is so low that you should be able to sink with any opamp.
Read the datasheet specification of your opamp.