Stereoisomerism occurs when the bond connectivity is same but the spatial arrangement of more than one type is possible. Stereoisomerism finds vast use in orgaic chemistry, mainly biochemistry as all the biomolecules, are generally stereospecific in their actions. Stereoisomerism in limited not only to organic compounds but also to inorganic compounds, mainly in co-ordination complexes. Stereoisomers include cis and trans isomers, chiral isomers, compound wilth different conformation of chelate rings and other isomers that differ only in the geometry of attachement of the metal ion.
Select the incorrect statement:

Options

A. trans from of `[CoCl_(2)("trien")]^(+)` has 3 coplanar chelate ring
B. `[Pt(py)(NH_(3))(NO_(2))(Cl)(Br)(I)]` has 15 geometrical isomers
C. Carboxylic group of salicylate ion is cis and tans to tertiary nitorgen in `[Co("tren")("sal")]^(+)`
D. `[Pt(NH_(3))_(2)(py)_(2)Cl(2)]^(2+)` complex has 5 non chiral isomer.

Explanation

To solve the question regarding stereoisomerism and to identify the incorrect statement among the provided options, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding Stereoisomerism**:
- Stereoisomerism occurs when compounds have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of those atoms. This is crucial in organic and inorganic chemistry, particularly in biochemistry.

2. **Analyzing the Options**:
- We have four options to evaluate. We need to determine which of these statements is incorrect.

3. **Option 1**: "Trans form of [CoCl2(trien)]^+ has three co-planar chelate rings."
- To verify this, we need to draw the structure of [CoCl2(trien)]^+. The trien ligand (triethylenetetramine) coordinates with cobalt, and the two chloride ions also coordinate. The trans form indicates that the two chloride ions are opposite each other, leading to a planar arrangement of the chelate rings.
- **Conclusion**: This statement is correct.

4. **Option 2**: "PTPYNS3NO2ClBr has 15 geometrical isomers."
- The number of geometrical isomers can be calculated based on the coordination number and the types of ligands present. For a complex with multiple different ligands, the number of isomers can be significant.
- **Conclusion**: This statement is correct, as it is possible for such a complex to have 15 geometrical isomers.

5. **Option 3**: "Carboxylic group of salicylate ion is cis and trans to tertiary nitrogen in [Co(trien)(COO)]^+."
- In this case, we need to analyze the salicylate ion's structure and its relation to the cobalt complex. The carboxylic group can exhibit cis and trans configurations with respect to the nitrogen atoms in the chelate ring.
- **Conclusion**: This statement is correct, as the carboxylic group can indeed be in cis or trans positions relative to the nitrogen.

6. **Option 4**: "PTNS3 whole to Py2Cl2 complex has 5 chiral isomers."
- To evaluate this, we need to consider the structure of the complex. A complex with a certain number of ligands and symmetry can lead to chiral isomers. However, it is stated that this complex has 4 non-chiral isomers, which means it cannot have 5 chiral isomers.
- **Conclusion**: This statement is incorrect.

### Final Answer:
The incorrect statement is **Option 4**: "PTNS3 whole to Py2Cl2 complex has 5 chiral isomers."