1.Types of DataTypes in C?
    • Primitive data type
    • Derived data type
    • User defined data type
Primitive data type
                char, int, float, double
Derived data type
                signed/unsigned char, signed/unsigned int, signed/unsigned long, long double
User defined data type
                structure, union, Enum, array

2. What is range of data types in c? How to find it? 

Below range & format specifier are based on 32 bit gcc compiler.
 
 DATA TYPE  MEMORY (BYTES)  RANGE  FORMAT SPECIFIER
signed char  1  -128 to 127  %c
 unsigned char 1   0 to 255  %c
short int 2  -32,768 to 32,767  %d
unsigned short int  2  0 to 65,535  %u
 unsigned int 4 0 to 4,294,967,295   %u
 int 4 -2,147,483,648 to 2,147,483,647   %d
 float 4 1.2E-38 to 3.4E+38   %f
 double 8 2.3E-308 to 1.7E+308  %lf

To Find:
            For signed data types, 
                    -2^(n-1) to (2^(n-1))-1
            For unsigned data types, 
                    (2^n) – 1 
If we are minded the above formula we can easily find the range of datatype.