"All of us are playing well and in a good space," said Sitak.
"There is real confidence among the group.
"We know what we can achieve as a team."
Sitak enjoyed his first Wimbledon experience - "I loved the traditions. I want to wear all-white in every tournament from now on" - and had an epic first day.
"We went to five sets, winning 10-8 in the fifth, on one of the hottest days ever recorded at Wimbledon. It was more than 40C and we were on court for four hours."
Sitak, who was beaten by the eventual finalists in both the men's doubles and mixed doubles, took great heart from his SW19 spell.
"I can see that we can be there, at that level," said Sitak. "I'm improving and learning every day, all the time."
That improvement will be necessary against a strong Indian team. They include Yuki Bhambri (world No 156) and Somdev Devvarman (173 but has been as high as 90) as well as top-20 doubles player Ropan Bopana, who was due to play in the Wimbledon men's doubles final overnight (NZT).
"They are a very good team with a lot of quality," said Sitak.
The tie opens on Friday with two singles matches, followed by the doubles on Saturday and reverse singles on Sunday.