Can interrupts be interrupted in OS? How can we handle it?  

23 minutes ago, Nandhini said:

Can interrupts be interrupted in OS?

Some NMIs can't be masked.
If that is what the question means.

24 minutes ago, Nandhini said:

How can we handle it?  

Maybe you could try to formulate a question that has some appropriate context?

13 minutes ago, Ghideon said:

Some NMIs can't be masked.

NMI is literal shortcut of non maskable interrupt..

https://en.m.wikipedia.org/wiki/Non-maskable_interrupt

7 minutes ago, Sensei said:

NMI is literal shortcut of non maskable interrupt.

True. I did not bother writing a detailed answer since the question was not very clear. Hoped OP could clarify. 

Many Interrupts, including some NMIs on some plattforms, can be masked. Masking NMIs may require specific methods.