Security and Intelligence Services (India) Ltd (SIS) shares made modest gains on their market debut on Thursday after a $122 million initial public offering, suggesting investors were cautious of the stock’s high valuations. The stock rose as much as 8 percent to a high of 879.80 rupees in early trade, compared with the IPO issue price of 815 rupees. By 0600 GMT, it was trading 5 percent higher at 855.75 rupees, in a Mumbai market that was down 0.24 percent. SIS, the second-largest security services provider by revenue in…