British ministers have said both these issues would be raised during Modi's visit, though these would be made privately rather than through "megaphone diplomacy".
The prime minister has expressed confidence that his visit to Sweden and Britain will be useful in enhancing India's ties with the two European countries.
The two Prime Ministers will hold bilateral talks on Tuesday.
Congress chief Rahul Gandhi in a late night tweet on Wednesday thanked Prime Minister Narendra Modi for breaking his silence on the rape cases and demanded that the latter should also specify a timeline for the justice promised to the victims.
Prime Ministers from the other Nordic countries, Denmark, Finland, Iceland and Norway are also expected to be in Stockholm for th Nordic-Indian summit.
In the United Kingdom, the prime minister will attend the Commonwealth Heads of Government Meeting (CHOGM), besides exploring ways to further deepen ties between the two countries, the Ministry of External Affairs (MEA) had earlier said.
While returning from Britain on April 20, he will stop over in Germany where he will a meet German Chancellor Angela Merkel.
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Firstly for him, coming to this league for the first time, and then we had to take on all this information he was giving to us. Guardiola and his players will have the chance to celebrate properly on Sunday when they host Swansea in their next fixture.
India and Sweden will sign a general security agreement, which is a precondition for Sweden to share sensitive technology with India if, for instance, Swedish company Saab is chosen to build fighter jets in India.
This will be followed by the launch of a new Ayurvedic Centre of Excellence, marked by an MoU between the All India Institute of Ayurveda and College of Medicine in the UK.
The event, billed as the centrepiece of the "Living Bridge" theme of the India-UK bilateral visit, will involve PM Modi addressing questions from across the world which have already been received via social media and some via live video link.
PM Modi's statement came on a day when the top court took a strict note of the attempt by a group of lawyers in Jammu to prevent state police from filing a charge sheet at the local court last week in Kathua rape case.
With economic ties being an important pillar of the India-Britain bilateral relationship, Modi and May will attend a CEOs Forum.
"The Commonwealth is a unique multilateral grouping that not only provides useful assistance to its developing country members, particularly the small states and small-island developing states, but also has a strong global voice for development issues", PM Modi said.
Also to be seen is in what format Britain raises issues around the treatment of religious minorities in India, and the detention of Jagtar Singh Johal, a British citizen who remains in custody in India after being arrested past year.