For sure it is, not sure to what level though. Some evident points being
1. Remember Sana talk of Himanshi just before she entered
2.In the start Sana, Paras definitely talked indirectly about some script. "Tu mujhe mat sikha", "Mujhe pata hai", "Tu gamer hai bada aaya scriptwala, mei palat dungi".
Even many a times Mahira and Paras talk things indirectly "pata haina kyu", etc. otherwise Mahira who cant take a word against her , why does she go and manao Sana everytime. Also Paras hatered for Sana is clearly coz of Sana not listening to his directions, so is with Shukla.
3. There was this fight between Rashmi and Paras, where he said use sab pata tha to mujhe mat bol. Wo janti thi sab. Even Rashmi paras have many conversations about "script", zyada mat beh ja tere lie bol rahi hu.
4. You think Salman with such big ego would listen so much from Paras and backtrack? Another drama
5. Madhu and Vishal fights was clearly so scripted in many parts.
6. Remember when they got food from their homes? Paras was emotional and said that his mom did not send this food. I think his sentiments were for Akanksha thinking how much she is doing.
7.Paras ka revelation about creatives ne bola tha and things. His finger surgery was purely faked. That week maybe he was in least vote list and creatives told him to do certain things in return of his safety.
8. Sid nominating Paras and both Paras and him were like hume pata hai kya kar rahe hia
9. I remember when rashmi came, she told multiple times tumlog ko pata nahi hai hume kya kya jhelna pada hai. Maybe creatives were angry about her not following some tracks as directed by them. Her extreme high reactions sometimes and going totally soft sometimes is strange too.
10. All the shocking evictions and Arti and Shefali being dragged is another hint. Strong contestants were never kept.
11. Rashmi knew Arhan and Sid are part of season. And the kind of ankho se ishare I see between Sana and paras I wont be suprised if they have planned few things outside the house, like the Par-Mahi-Sana triangle.
12. Sis is clearly instructed to change his aggressive image and go to a funny playboy image as is seen from his flirtations with so many women in the house. Otherwise Sid has been the very reserved and alpha male kinds of person before he came back after hospitalization. Remeber him saying to the mike dekho big boss poke kia and things, he never did that before.He was clearly given many instructions and may be showed a few clips too. Asim has caught all of this and maybe he is playing the game like Sid wanted to play, thats the reason he has issues with him and they blow out of proportion whenever there is a small disagreement between the two.
13. Vikas was another part of the script and he went to change the dynamics which was very clear.
I will try adding a few more as and when i remember
Overall I wont say it is 100% scripted , but yes before the show starts there are many characters that are build up and a storyline. If not all of them few prominent ones for sure are informed well ahead how the show will go. paras clearly knows so many things and thats the reason Sid has warmed upto him. And yes many a times people do get carried away and deviate from the plot and the script keeps changing as per the audience reaction.