• Seeta, Rajinder and Surinder are children of Mr. and Mrs. Aggarwal.
• Renu, Raja and Sunil are children of Mr and Mrs. Malhotra.
• Sunil and Seeta are a married couple and Ashok and Sanjay are their children.
• Geeta and Rakesh are children of Mr. and Mrs. Gupta.
• Geeta is married to Surinder and has three children named Rita, Sonu and Raju.
Mohan is the son of Arun's father's sister. Prakash is the son of Reva, who is the mother of Vikas and grandmother of Arun. Pranab is the father of Neela and the grandfather of Mohan. Reva is the wife of Pranab. How is the wife of Vikas related to Neela?
Step 1: Place the elder couple.
Reva is the wife of Pranab. So the senior couple is \(\boxed{\text{Pranab} \leftrightarrow \text{Reva}}\).
Step 2: List children of the senior couple.
Given: Reva is the \(\textit{mother of Vikas}\) and \(\textit{grandmother of Arun}\).
Also: Pranab is the \(\textit{father of Neela}\) and \(\textit{grandfather of Mohan}\).
\(\Rightarrow\) Children of Pranab-Reva include at least \(\boxed{\text{Vikas},\ \text{Neela},\ \text{Arun's father (say }X\text{)}}\). Thus, \(Vikas,\ Neela,\ X\) are siblings.
Step 3: Fit Mohan and Arun.
"Mohan is the son of Arun's father's sister" \(\Rightarrow\) Mohan is son of \(\boxed{X\text{'s sister}}.\) Since \(X\)'s sister can be Neela (child of Pranab-Reva), Mohan can be Neela's son.
Check with the other clue: "Pranab is the grandfather of Mohan" — true if Mohan is Neela's son.
Also, "Reva is grandmother of Arun" — true since Arun is son of \(X\) (another child of Pranab-Reva).
All statements are consistent with the sibling set \(\{Vikas,\ Neela,\ X\}\).
Step 4: Relationship asked.
We need the relation of \(\boxed{\text{Vikas's wife}}\) to \(\boxed{\text{Neela}}\). Because Vikas and Neela are brother and sister, Vikas's wife is Neela's \(\boxed{\text{Sister-in-law}}\).
\[ \boxed{\text{Sister-in-law}} \]