Pronunciation of h in Serbian
"The phoneme /x/ (written as h) has been volatile in eastern South Slavic dialects. In Serbian and
some Croatian dialects (including some of those in Slavonia), it has been replaced with /j/, /v/, or
elided, and subsequent standardization sanctioned those forms:" ~ wikipedia https://en.wikipedia.org/wiki/Comparison_of_standard_Bosnian,_Croatian,_Montenegrin_and_Serbian#Accentuation

Now I understand that they are written as j or v if they are pronounced so, but how is it pronounced when it is still written, for example hteti.

Question

Pronunciation of h in Serbian
"The phoneme /x/ (written as h) has been volatile in eastern South Slavic dialects. In Serbian and 
     some Croatian dialects (including some of those in Slavonia), it has been replaced with /j/, /v/, or 
     elided, and subsequent standardization sanctioned those forms:" ~ wikipedia   https://en.wikipedia.org/wiki/Comparison_of_standard_Bosnian,_Croatian,_Montenegrin_and_Serbian#Accentuation

Now I understand that they are written as  j  or  v  if they are pronounced so, but how is it pronounced when it is still written, for example  hteti.

Answer

Sheperd, you was talking about some dialects in Serbo-Croatian. The sound H(X) should be pronounced in a formal speech. The pronounce is very similar to your Have, Hand, Hard ...

Regards