What is the range ?

[boral]

What is the allowable range for integer constants and for real constants ( in exponential form ) in Pelles C ?

[Bitbeisser]

What is the allowable range for integer constants and for real constants ( in exponential form ) in Pelles C ?

Pretty much the same as for any other x86 compiler and depending on what exact "integer" and/or "real" type you are talking about.
In general, the limits (range as you call it) are defined in limits.h. Further "real" limits are also defined in float.h.

This information is also readily available in the Pelle's C IDE Help file... 

Ralf