There is no official age limit to be called for a kpop audition.
However, idols usually go through the following steps:

• become trainee before 16yo
• train for some years
• debut around their 16~22yo range

Therefore, if you are around 16~19yo region, then you are a little late.

However, if you have an incredible talent and an outstanding shining star upon you, then you've might have a chance. This is very rare to happen, but a few exceptions are:

• Irene (Red Velvet)

  
  She became a trainee at 18yo in 2009, just after her high school. Trained for 5 years under SM Entertainment and debuted in 2014 at 23yo.

• Solar (MAMAMOO)

  
  She became a trainee under RBW Entertainment in 2011 at 20yo, trained for 3 years and debuted at 23yo.

• Miya (GWSN)

  
  She joined GWSN in 2018 and debuted after 4 months at 25yo.

On the other side, agencies have no problem to take on trainees under 10:

• JYPe Twice’s Jihyo (born in 1997) trained for 10 years before her debut with Twice, in 2015. This means she entered JYPe in 2005, when she was just 8-years-old!
• JYPe Stray Kids Chan (born 1997) trained for 7 years before his debut with SKiz, in 2018. He entered the agency in 2010, he was only 13-years-old.

Further Reading

[ 1 ] Does JYP accept foreigners?

[ 2 ] Can an Indian girl join K-pop?

[ 3 ] What is the Black Ocean in Kpop?

[ 4 ] How do I audition for K-pop online?